Foamed polypropylene composition

ABSTRACT

The present invention is directed to a polypropylene composition (C) comprising a heterophasic propylene copolymer and an inorganic filler, the use of said polypropylene composition (C) for the production of a foamed article and a foamed article obtained from said polypropylene composition (C).

The present invention is directed to a polypropylene composition (C)comprising a heterophasic propylene copolymer and an inorganic filler,the use of said polypropylene composition (C) for the production of afoamed article and a foamed article obtained from said polypropylenecomposition (C).

Plastic materials featured by a reduced weight with preservation of themechanical property profile are gaining more and more interest in theautomotive industry since the European Union has approved tough CO₂limits which mandate the car manufacturer to cut emission from current160 g/km to 120 g/km or below. Thus, there is a need for weight savingconcepts in order to fulfil said legislation.

The foam injection-moulding (FIM) technology can be used to producelow-density parts. It can be applied for visible and non-visibleautomotive parts. Foamed parts have the advantage of reduced density,low shrinkage and warpage, but the mechanical properties and surfaceappearance of the parts are poor whereupon the majority of foamed partsare not used for visible interior or exterior applications.

Accordingly, there is a need in the art for a polypropylene compositionwhich after a step of injection-moulding foaming featured by homogeneoussurface appearance and balanced mechanical properties.

Therefore, it is an object of the present invention to provide afoamable polypropylene composition applicable for the preparation of afoamed article having homogeneous/good surface appearance and mechanicalproperties.

The finding of the present invention is to provide a polypropylenecomposition (C) comprising a heterophasic propylene copolymer and aninorganic filler.

Accordingly, the present invention is directed to a polypropylenecomposition (C), comprising

-   a) a first heterophasic propylene copolymer (HECO1) having a    comonomer content of the xylene soluble fraction (XCS) equal or    above 40.0 mol-%, said first heterophasic propylene copolymer    comprising    -   i) a first matrix being a first propylene polymer (M1) and    -   ii) a first elastomeric propylene copolymer (E1) being dispersed        in said first matrix,-   b) a second heterophasic propylene copolymer (HECO2) having a    comonomer content of the xylene soluble fraction (XCS) below 39.0    mol-%, said second heterophasic propylene copolymer comprising    -   iii) a second matrix being a second propylene polymer (M2) and    -   iv) a second elastomeric propylene copolymer (E1) being        dispersed in said second matrix,-   c) an inorganic filler (F),-   d) optionally a high density polyethylene (HDPE), and-   e) optionally a plastomer (PL) being a copolymer of ethylene and a    C₄ to C₈ α-olefin.

It was surprisingly found that a foamed part obtained from apolypropylene composition (C) comprising two different heterophasicpropylene copolymers is featured by excellent mechanical properties andsurface appearance. The dispersed phase of the heterophasic system canhave a bimodal molecular weight distribution in order to assure goodbalance between mechanics and surface appearance. Additionally, a highdensity polyethylene (HDPE) and other additives can be used forimprovement of the scratch resistance which is especially useful forinterior applications. The compositions are suitable for chemical aswell as physical foaming.

According to one embodiment of the present invention, the xylene solublefraction (XCS) of the second heterophasic copolymer (HECO2) has anintrinsic viscosity (IV) above 3.5 dl/g.

According to another embodiment of the present invention, thepolypropylene composition (C) comprises

-   a) 40.0 to 60.0 wt.-% of the first heterophasic propylene copolymer    (HECO1),-   b) 21.0 to 31.0 wt.-% of the second heterophasic propylene copolymer    (HECO2),-   c) 10.0 to 20.0 wt.-% of the inorganic filler (F),-   d) optionally 2.0 to 10.0 wt.-% of the high density polyethylene    (HDPE), and-   e) optionally 5.0 to 15.0 wt.-% of the plastomer (PL) being a    copolymer of ethylene and a C₄ to C₈ α-olefin, based on the overall    polypropylene composition (C).

According to a further embodiment of the present invention, the matrixof the first heterophasic propylene copolymer (HECO1) being the firstpropylene polymer (M1) has a melt flow rate MFR₂ (230° C.) determinedaccording to ISO 1133 in the range of 120 to 500 g/10 min and the matrixof the second heterophasic propylene copolymer (HECO2) being the secondpropylene polymer (M2) has a melt flow rate MFR₂ (230° C.) determinedaccording to ISO 1133 in the range of 40 to 170 g/10 min.

According to still another embodiment of the present invention, thefirst heterophasic propylene copolymer (HECO1) has

-   i) a melt flow rate MFR₂ (230° C.) determined according to ISO 1133    in the range of 50 to 90 g/10 min, and/or-   ii) a comonomer content in the range of 20.0 to 50.0 mol-%, and/or-   iii) a xylene soluble fraction (XCS) in the range of 10.0 to 35.0    wt.-%.

According to one embodiment of the present invention, the secondheterophasic propylene copolymer (HECO2) has

-   i) a melt flow rate MFR₂ (230° C.) determined according to ISO 1133    in the range of 1.0 to 15 g/10 min, and/or-   ii) a comonomer content in the range of 5.0 to 30.0 mol-%, and/or-   iii) a xylene soluble fraction (XCS) in the range of 20.0 to 40.0    wt.-%.

It is especially preferred that the first propylene polymer (M1) and/orthe second propylene polymer (M2) are propylene homopolymers.

According to one embodiment of the present invention, the firstelastomeric propylene copolymer (E1) and/or the second elastomericpropylene copolymer (E2) are copolymers of propylene and ethylene.

According to another embodiment of the present invention, thepolypropylene composition (C) has a melt flow rate MFR₂ (230° C.)determined according to ISO 1133 in the range of 10 to 40 g/10 min.

According to a further embodiment of the present invention, theplastomer (PL) is a copolymer of ethylene and 1-octene.

It is especially preferred that the inorganic filler (F) is talc and/orwollastonite.

According to one embodiment of the present invention, the polypropylenecomposition (C) is a foamable polypropylene composition.

The present invention is further directed to the use of thepolypropylene composition (C) as described above for the production of afoamed article.

Further, the present invention is directed to a foamed article,comprising the polypropylene composition (C) as described above.

It is especially preferred that said foamed article is an automotivearticle.

In the following, the present invention is described in more detail.

The Polypropylene Composition (C)

The inventive polypropylene composition (C) comprises a firstheterophasic propylene copolymer (HECO1) comprising a first matrix beinga propylene polymer (M1) and a first elastomeric propylene copolymer(E1) and a second heterophasic propylene copolymer (HECO2) comprising asecond matrix being a propylene polymer (M2) and a second elastomericpropylene copolymer (E2).

Accordingly, the inventive polypropylene composition (C) comprises aheterophasic system comprising matrix (M) formed by the first propylenepolymer (M1) and the second propylene polymer (M2), and the firstelastomeric propylene copolymer (E1) and the second elastomericpropylene copolymer (E2) are dispersed in said matrix (M). Thus thematrix (M) contains (finely) dispersed inclusions being not part of thematrix (M) and said inclusions contain the first elastomeric propylenecopolymer (E1) and the second elastomeric propylene copolymer (E2). Theterm inclusion indicates that the matrix (M) and the inclusion formdifferent phases as defined below.

Further, the inventive polypropylene composition comprises an inorganicfiller (F).

Accordingly, it is preferred that the polypropylene composition (C)comprises, more preferably consists of, 60 to 95 wt.-% of the matrix(M), more preferably 70 to 90 wt.-%, still more preferably 75 to 80wt.-% and 5 to 40 wt.-% of the dispersed phase comprising the firstelastomeric propylene copolymer (E1) and the second elastomericpropylene copolymer (E2), more preferably 10 to 30 wt.-%, still morepreferably 20 to 25 wt.-% and 10 to 20 wt.-% of the inorganic filler(F), more preferably 12 to 18 wt.-%, still more preferably 13 to 16wt.-%, based on the overall weight of the polypropylene composition (C).

Preferably, the polypropylene composition (C) contains the firstpropylene polymer (M1) and the second propylene polymer (M2) forming thematrix (M) in a ratio of 1:1 to 3:1 and the first elastomeric propylenecopolymer (E1) and the second elastomeric propylene copolymer (E2) in aratio of 1:1 to 3:1. Accordingly, it is preferred that the polypropylenecomposition (C) comprises, 40 to 63 wt.-%, more preferably 46 to 60wt.-%, still more preferably 50 to 53 wt.-% of the first propylenepolymer (M1), 20 to 32 wt.-%, more preferably 23 to 30 wt.-%, still morepreferably 25 to 27 wt.-% of the second propylene polymer (M2) and 3 to26 wt.-%, more preferably 7 to 20 wt.-%, still more preferably 13 to 17wt.-% of the first elastomeric propylene copolymer (E1) and 2 to 14wt.-%, more preferably 3 to 10 wt.-%, still more preferably 6 to 8 wt.-%of the second elastomeric propylene copolymer (E2) and 10 to 20 wt.-%more preferably 12 to 18 wt.-%, still more preferably 13 to 16 wt.-% ofthe inorganic filler (F), based on the overall weight of thepolypropylene composition (C).

According to a preferred embodiment of the present invention, thepolypropylene composition (C) further comprises a high densitypolyethylene (HDPE) and a plastomer (PL) being a copolymer of ethyleneand a C₄ to C₈ α-olefin. Accordingly, it is preferred that thepolypropylene composition (C) comprises, 30 to 53 wt.-%, more preferably36 to 50 wt.-%, still more preferably 40 to 43 wt.-% of the firstpropylene polymer (M1), 20 to 32 wt.-%, more preferably 23 to 30 wt.-%,still more preferably 25 to 27 wt.-% of the second propylene polymer(M2) and 3 to 20 wt.-%, more preferably 7 to 19 wt.-%, still morepreferably 10 to 17 wt.-% of the first elastomeric propylene copolymer(E1) and 2 to 14 wt.-%, more preferably 3 to 10 wt.-%, still morepreferably 6 to 8 wt.-% of the second elastomeric propylene copolymer(E2), 10 to 20 wt.-% more preferably 12 to 18 wt.-%, still morepreferably 13 to 16 wt.-% of the inorganic filler (F), 2 to 10 wt.-%,more preferably 3 to 8 wt.-%, still more preferably 4 to 6 wt.-% of thehigh density polyethylene (HDPE) and 5 to 15 wt.-%, more preferably 6 to11 wt.-%, still more preferably 7 to 9 wt.-% of the plastomer (PL),based on the overall weight of the polypropylene composition (C).

Preferably, the polypropylene composition (C) is obtained by asequential polymerization process wherein at least two, like three,reactors are connected in series. For example, said process comprisesthe steps of

-   a) polymerizing propylene and optionally ethylene in a first reactor    (R1) to obtain the first propylene polymer (M1),-   b) transferring the first propylene polymer (M1) into a second    reactor (R2),-   c) polymerizing in said second reactor (R2) in the presence of said    first propylene polymer (M1) propylene and optionally ethylene    obtaining the second propylene polymer (M2), said first propylene    polymer (M1) and said second propylene polymer (M2) form the matrix    (M),-   d) transferring the matrix (M) into a third reactor (R3),-   e) polymerizing in said third reactor (R3) in the presence of the    matrix (M) propylene and/or a C₄ to C₈ α-olefin, obtaining a third    polymer fraction, said polymer fraction is the first elastomeric    copolymer (E1),-   f) transferring the matrix (M) and the first elastomeric copolymer    (E1) into a fourth reactor (R4),-   g) polymerizing in said fourth reactor (R4) in the presence of the    matrix (M) and the first elastomeric propylene copolymer (E1)    propylene and/or a C₄ to C₈ α-olefin, obtaining a fourth polymer    fraction, said polymer fraction is the second elastomeric copolymer    (E2), said matrix (M) and said first elastomeric propylene copolymer    (E1) and said second elastomeric propylene copolymer form a    heterophasic propylene copolymer,-   h) optionally melt blending said heterophasic propylene copolymer    obtained in the fourth reactor (R4) with the inorganic filler (F),    optionally the high density polyethylene (HDPE) and optionally the    plastomer (PL).

Alternatively, the polypropylene composition (C) is obtained by meltblending the first heterophasic propylene copolymer (HECO1) comprising amatrix being the first propylene polymer (M1) and a dispersed phasebeing the first elastomeric propylene copolymer (E1), the secondheterophasic propylene copolymer (HECO2) comprising a matrix being thesecond propylene polymer (M2) and a dispersed phase being the secondelastomeric propylene copolymer (E2), the inorganic filler (F),optionally the high density polyethylene (HDPE) and optionally theplastomer (PL). Melt blending of said first heterophasic propylenecopolymer (HECO1) and said second heterophasic propylene copolymer(HECO2) results in a heterophasic system wherein the first propylenepolymer (M1) and the second propylene polymer (M2) form the matrix andthe first elastomeric propylene copolymer (E1) and the secondelastomeric propylene copolymer (E2) form the dispersed phase.

It is especially preferred that the polypropylene composition (C) isobtained by melt blending said first heterophasic propylene copolymer(HECO1) and said second heterophasic propylene copolymer (HECO2) withthe inorganic filler (F) and optionally the high density polyethylene(HDPE) and/or the plastomer (PL).

Accordingly, it is preferred that the polypropylene composition (C)comprises, 40 to 60 wt.-%, more preferably 41 to 59 wt.-%, still morepreferably 42 to 57 wt.-% of the first heterophasic propylene copolymer(HECO1), 21 to 31 wt.-%, more preferably 23 to 30 wt.-%, still morepreferably 25 to 27 wt.-% of the second heterophasic propylene copolymer(HECO2), 10 to 20 wt.-% more preferably 12 to 18 wt.-%, still morepreferably 13 to 16 wt.-% of the inorganic filler (F), optionally 2 to10 wt.-%, more preferably 3 to 8 wt.-%, still more preferably 4 to 6wt.-% of the high density polyethylene (HDPE) and optionally 5 to 15wt.-%, more preferably 6 to 11 wt.-%, still more preferably 7 to 9 wt.-%of the plastomer (PL), based on the overall weight of the polypropylenecomposition (C).

The polypropylene composition (C) of the present invention may includeadditives (AD). Accordingly, it is preferred that that the polypropylenecomposition (C) comprises, preferably consists of, 40 to 60 wt.-%, morepreferably 41 to 59 wt.-%, still more preferably 42 to 57 wt.-% of thefirst heterophasic propylene copolymer (HECO1), 21 to 31 wt.-%, morepreferably 23 to 30 wt.-%, still more preferably 25 to 27 wt.-% of thesecond heterophasic propylene copolymer (HECO2), 10 to 20 wt.-% morepreferably 12 to 18 wt.-%, still more preferably 13 to 16 wt.-% of theinorganic filler (F), optionally 2 to 10 wt.-%, more preferably 3 to 8wt.-%, still more preferably 4 to 6 wt.-% of the high densitypolyethylene (HDPE) and optionally 5 to 15 wt.-%, more preferably 6 to11 wt.-%, still more preferably 7 to 9 wt.-% of the plastomer (PL) and0.05 to 5 wt.-%, preferably 0.1 to 3 wt.-% of additives (AD), based onthe overall weight of the polypropylene composition (C). The additives(AD) are described in more detail below.

Preferably the polypropylene composition (C) of the invention does notcomprise (a) further polymer(s) different to the first propylene polymer(M1), the second propylene polymer (M2), the first elastomeric propylenecopolymer (E1), the second elastomeric propylene copolymer (E2), thehigh density polyethylene (HDPE) and the plastomer (PL) in an amountexceeding 5.0 wt.-%, preferably in an amount exceeding 3.0 wt.-%, morepreferably in an amount exceeding 2.5 wt.-%, based on the overall weightof the polypropylene composition (C).

It is preferred that the polypropylene composition (C) has a moderatemelt flow rate. Thus, it is preferred that the melt flow rate MFR₂ (230°C.) determined according to ISO 1133 of the polypropylene composition(C) is in the range of 10 to 40 g/10 min, more preferably in the rangeof 15 to 35 g/10 min, still more preferably in the range of 20 to 32g/10 min

Further, it is preferred that the polypropylene composition (C) isfeatured by a rather high flexural modulus. Accordingly, it is preferredthat the polypropylene composition (C) has a flexural modulus measuredon injection moulded specimens according to ISO 178 in the range of 1000to 3000 MPa, more preferably in the range of 1200 to 2800 MPa, stillmore preferably in the range of 1500 to 2700 MPa.

In the following, the first heterophasic propylene copolymer (HECO1),the second heterophasic propylene copolymer (HECO2), the high densitypolyethylene (HDPE), the plastomer (PL) and the inorganic filler (F) aredescribed in more detail.

The First Heterophasic Propylene Copolymer (HECO1)

The inventive polypropylene composition (C) comprises a firstheterophasic propylene copolymer (HECO1).

The first heterophasic propylene copolymer (HECO1) according to thisinvention comprises a matrix (M) being the first propylene polymer (M1)and dispersed therein an elastomeric propylene copolymer (E) being thefirst elastomeric propylene copolymer (E1). Thus the matrix (M) contains(finely) dispersed inclusions being not part of the matrix (M) and saidinclusions contain the elastomeric propylene copolymer (E). The terminclusion indicates that the matrix (M) and the inclusion form differentphases within the heterophasic propylene copolymer (HECO1). The presenceof second phases or the so called inclusions are for instance visible byhigh resolution microscopy, like electron microscopy or atomic forcemicroscopy, or by dynamic mechanical thermal analysis (DMTA).Specifically, in DMTA the presence of a multiphase structure can beidentified by the presence of at least two distinct glass transitiontemperatures.

Accordingly, the first heterophasic composition (HECO1) according tothis invention preferably comprises

-   (a) the (semi)crystalline first propylene polymer (M1) as the    matrix (M) and-   (b) the first elastomeric propylene copolymer (E1).

Preferably the weight ratio between the first propylene polymer (M1) andthe elastomeric propylene copolymer (E1) [M1/E1] of the firstheterophasic composition (HECO1) is in the range of 90/10 to 40/60, morepreferably in the range of 85/15 to 45/55, yet more preferably in therange of 83/17 to 50/50, like in the range of 82/18 to 60/40.

Preferably, the first heterophasic propylene copolymer (HECO1) accordingto this invention comprises as polymer components only the firstpropylene polymer (M1) and the first elastomeric propylene copolymer(E1). In other words, the first heterophasic propylene copolymer (HECO1)may contain further additives but no other polymer in an amountexceeding 5.0 wt.-%, more preferably exceeding 3.0 wt.-%, like exceeding1.0 wt.-%, based on the total first heterophasic propylene copolymer(HECO1). One additional polymer which may be present in such low amountsis a polyethylene which is a reaction by-product obtained by thepreparation of the first heterophasic propylene copolymer (HECO1).Accordingly, it is in particular appreciated that the instant firstheterophasic propylene copolymer (HECO1) contains only the firstpropylene polymer (M1), the first elastomeric propylene copolymer (E1)and optionally polyethylene in amounts as mentioned in this paragraph.

The first heterophasic propylene copolymer (HECO1) applied according tothis invention is featured by a rather high melt flow rate. Accordingly,the first heterophasic propylene copolymer (HECO1) has a melt flow rateMFR₂ (230° C.) in the range of 50 to 90 g/10 min, preferably in therange of 60 to 80 g/10 min, more preferably in the range of 65 to 71g/10 min.

Preferably, it is desired that the first heterophasic propylenecopolymer (HECO1) is thermo mechanically stable. Accordingly, it isappreciated that the first heterophasic propylene copolymer (HECO1) hasa melting temperature of at least 160° C., more preferably in the rangeof 160 to 167° C., still more preferably in the range of 162 to 165° C.

The first heterophasic propylene copolymer (HECO1) comprises apart frompropylene also comonomers. Preferably the first heterophasic propylenecopolymer (HECO1) comprises apart from propylene ethylene and/or C₄ toC₈ α-olefins. Accordingly, the term “propylene copolymer” according tothis invention is understood as a polypropylene comprising, preferablyconsisting of, units derivable from

(a) propyleneand(b) ethylene and/or C₄ to C₈ α-olefins.

Thus, the first heterophasic propylene copolymer (HECO1), i.e. firstpropylene polymer (M1) as well as the first elastomeric propylenecopolymer (E1), can comprise monomers copolymerizable with propylene,for example comonomers such as ethylene and/or C₄ to C₈ α-olefins, inparticular ethylene and/or C₄ to C₈ α-olefins, e.g. 1-butene and/or1-hexene. Preferably, the first heterophasic propylene copolymer (HECO1)according to this invention comprises, especially consists of, monomerscopolymerizable with propylene from the group consisting of ethylene,1-butene and 1-hexene. More specifically, the first heterophasicpropylene copolymer (HECO1) of this invention comprises—apart frompropylene—units derivable from ethylene and/or 1-butene. In a preferredembodiment, the first heterophasic propylene copolymer (HECO1) accordingto this invention comprises units derivable from ethylene and propyleneonly. Still more preferably the first propylene polymer (M1) as well asthe first elastomeric propylene copolymer (E1) of the first heterophasicpropylene copolymer (HECO1) contain the same comonomers, like ethylene.

Additionally, it is appreciated that the first heterophasic propylenecopolymer (HECO1) preferably has a rather low total comonomer content,preferably ethylene content. Thus, it is preferred that the comonomercontent of the first heterophasic propylene copolymer (HECO1) is in therange from 4.0 to 25.0 mol-%, preferably in the range from 6.0 to 18.0mol-%, more preferably in the range from 10.0 to 13.0 mol-%.

The xylene cold soluble (XCS) fraction measured according to accordingISO 16152 (25° C.) of the first heterophasic propylene copolymer (HECO1)is in the range of 10.0 to 40.0 wt.-%, preferably in the range from 15.0to 30.0 wt.-%, more preferably in the range from 17.0 to 25.0 wt.-%,still more preferably in the range from 19.0 to 22.0 wt.-%.

Further it is appreciated that the xylene cold soluble (XCS) fraction ofthe first heterophasic propylene copolymer (HECO1) is specified by itsintrinsic viscosity. A low intrinsic viscosity (IV) value reflects a lowweight average molecular weight. For the present invention it isappreciated that the xylene cold soluble fraction (XCS) of the firstheterophasic propylene copolymer (HECO1) has an intrinsic viscosity (IV)measured according to ISO 1628/1 (at 135° C. in decalin) in the range of1.0 to 3.3 dl/g, preferably in the range of 1.5 to 3.2 dl/g, morepreferably in the range of 1.7 to 3.0 dl/g.

Additionally, it is preferred that the comonomer content, i.e. ethylenecontent, of the xylene cold soluble (XCS) fraction of the firstheterophasic propylene copolymer (HECO1) is equal or above 40 mol-%,preferably in the range of 40 to 55 mol-%, more preferably in the rangeof 42 to 50 mol.-%, yet more preferably in the range of 43 to 46 mol.-%.The comonomers present in the xylene cold soluble (XCS) fraction arethose defined above for the first propylene polymer (M1) and the firstelastomeric propylene copolymer (E1), respectively. In one preferredembodiment the comonomer is ethylene only.

The first heterophasic propylene copolymer (HECO1) can be furtherdefined by its individual components, i.e. the first propylene polymer(M1) and the first elastomeric propylene copolymer (E1).

The first propylene polymer (M1) can be a propylene copolymer or apropylene homopolymer, the latter being preferred.

In case the first propylene polymer (M1) is a propylene copolymer, thefirst propylene polymer (M1) comprises monomers copolymerizable withpropylene, for example comonomers such as ethylene and/or C₄ to C₈α-olefins, in particular ethylene and/or C₄ to C₆ α-olefins, e.g.1-butene and/or 1-hexene. Preferably the first propylene polymer (M1)according to this invention comprises, especially consists of, monomerscopolymerizable with propylene from the group consisting of ethylene,1-butene and 1-hexene. More specifically the first propylene polymer(M1) of this invention comprises—apart from propylene—units derivablefrom ethylene and/or 1-butene. In a preferred embodiment the firstpropylene polymer (M1) comprises units derivable from ethylene andpropylene only. The first propylene polymer (M1) according to thisinvention has a melt flow rate MFR₂ (230° C./2.16 kg) measured accordingto ISO 1133 in the range of 120 to 500 g/10 min, more preferably in therange of 130 to 200 g/10 min, still more preferably in the range of 140to 170 g/10 min.

As mentioned above the first heterophasic propylene copolymer (HECO1) isfeatured by a low comonomer content. Accordingly, the comonomer contentof the first propylene polymer (M1) is in the range of 0.0 to 5.0 mol-%,yet more preferably in the range of 0.0 to 3.0 mol-%, still morepreferably in the range of 0.0 to 1.0 mol-%. It is especially preferredthat the first propylene polymer (M1) is a propylene homopolymer.

The first heterophasic propylene copolymer (HECO1) preferably comprises60 to 95 wt.-%, more preferably 60 to 90 wt.-%, still more preferably 65to 87 wt.-% of the first propylene polymer (M1), based on the totalweight of the first heterophasic propylene copolymer (HECO1).

Additionally, the first heterophasic propylene copolymer (HECO1)preferably comprises 5 to 40 wt.-%, more preferably 10 to 40 wt.-%,still more preferably 13 to 35 wt.-% of the first elastomeric propylenecopolymer (E1), based on the total weight of the first heterophasicpropylene copolymer (HECO1).

Thus, it is appreciated that the first heterophasic propylene copolymer(HECO1) preferably comprises, more preferably consists of, 60 to 95wt.-%, preferably 60 to 90 wt.-%, more preferably 65.0 to 87.0 wt.-% ofthe first propylene polymer (M1) and 5 to 40 wt.-%, preferably 10 to 40wt.-%, more preferably 13.0 to 35.0 wt.-% of the first elastomericpropylene copolymer (E1), based on the total weight of the firstheterophasic propylene copolymer (HECO1).

Accordingly, a further component of the first heterophasic propylenecopolymer (HECO1) is the elastomeric propylene copolymer (E1) dispersedin the matrix (M) being the first propylene polymer (M1). Concerning thecomonomers used in the first elastomeric propylene copolymer (E1) it isreferred to the information provided for the first heterophasicpropylene copolymer (HECO1). Accordingly, the first elastomericpropylene copolymer (E1) comprises monomers copolymerizable withpropylene, for example comonomers such as ethylene and/or C₄ to C₈α-olefins, in particular ethylene and/or C₄ to C₆ α-olefins, e.g.1-butene and/or 1-hexene. Preferably, the first elastomeric propylenecopolymer (E1) comprises, especially consists of, monomerscopolymerizable with propylene from the group consisting of ethylene,1-butene and 1-hexene. More specifically, the first elastomericpropylene copolymer (E1) comprises—apart from propylene—units derivablefrom ethylene and/or 1-butene. Thus, in an especially preferredembodiment the first elastomeric propylene copolymer (E1) comprisesunits derivable from ethylene and propylene only.

The comonomer content of the first elastomeric propylene copolymer (E1)preferably is in the range of 35.0 to 70.0 mol-%, more preferably in therange of 37.0 to 60.0 mol-%, still more preferably in the range of 40.0to 50.0 mol-%.

The first heterophasic propylene copolymer (HECO1) as defined in theinstant invention may contain up to 5.0 wt.-% additives, like nucleatingagents and antioxidants, as well as slip agents and antiblocking agents.Preferably the additive content (without α-nucleating agents) is below3.0 wt.-%, like below 1.0 wt.-%.

According to a preferred embodiment of the present invention, the firstheterophasic propylene copolymer (HECO1) contains an α-nucleating agent.

According to this invention the alpha nucleating agent is not anadditive (AD).

The alpha-nucleating agent is preferably selected from the groupconsisting of

-   (i) salts of monocarboxylic acids and polycarboxylic acids, e.g.    sodium benzoate or aluminum tert-butylbenzoate, and-   (ii) dibenzylidenesorbitol (e.g. 1,3:2,4 dibenzylidenesorbitol) and    C₁-C₈-alkyl-substituted dibenzylidenesorbitol derivatives, such as    methyldibenzylidenesorbitol, ethyldibenzylidenesorbitol or    dimethyldibenzylidenesorbitol (e.g. 1,3:2,4 di(methylbenzylidene)    sorbitol), or substituted nonitol-derivatives, such as    1,2,3,-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol,    and-   (iii) salts of diesters of phosphoric acid, e.g. sodium    2,2′-methylenebis (4,6-di-tert-butylphenyl) phosphate or    aluminium-hydroxy-bis[2,2′-methylene-bis(4,6-di-t-butylphenyl)phosphate],    and-   (iv) vinylcycloalkane polymer or vinylalkane polymer, and-   (v) mixtures thereof.

Preferably the alpha-nucleating agent comprised in the composition ofthe invention is vinylcycloalkane polymer and/or vinylalkane polymer,more preferably vinylcycloalkane polymer, like vinylcyclohexane (VCH)polymer. Vinyl cyclohexane (VCH) polymer is particularly preferred asα-nucleating agent. It is appreciated that the amount ofvinylcycloalkane, like vinylcyclohexane (VCH), polymer and/orvinylalkane polymer, more preferably of vinylcyclohexane (VCH) polymer,in the composition is not more than 500 ppm, preferably not more than200 ppm, more preferably not more than 100 ppm, like in the range of 0.1to 500 ppm, preferably in the range of 0.5 to 200 ppm, more preferablyin the range of 1 to 100 ppm. Furthermore, it is appreciated that thevinylcycloalkane polymer and/or vinylalkane polymer is introduced intothe composition by the BNT technology. With regard to the BNT-technologyreference is made to the international applications WO 99/24478, WO99/24479 and particularly WO 00/68315. According to this technology acatalyst system, preferably a Ziegler-Natta procatalyst, can be modifiedby polymerizing a vinyl compound in the presence of the catalyst system,comprising in particular the special Ziegler-Natta procatalyst, anexternal donor and a cocatalyst, which vinyl compound has the formula:

CH₂═CH—CHR³R⁴

wherein R³ and R⁴ together form a 5- or 6-membered saturated,unsaturated or aromatic ring or independently represent an alkyl groupcomprising 1 to 4 carbon atoms, and the modified catalyst is preferablyused for the preparation of the heterophasic composition (HECO) presentin the modified polypropylene composition (mPP). The polymerized vinylcompound acts as an alpha-nucleating agent. The weight ratio of vinylcompound to solid catalyst component in the modification step of thecatalyst is preferably of up to 5 (5:1), more preferably up to 3 (3:1),like in the range of 0.5 (1:2) to 2 (2:1).

Such nucleating agents are commercially available and are described, forexample, in “Plastic Additives Handbook”, 5th edition, 2001 of HansZweifel (pages 967 to 990).

The first heterophasic propylene copolymer (HECO1) can be produced byblending the first propylene polymer (M1) and the first elastomericpropylene copolymer (E1). However, it is preferred that the firstheterophasic propylene copolymer (HECO1) is produced in a sequentialstep process, using reactors in serial configuration and operating atdifferent reaction conditions. As a consequence, each fraction preparedin a specific reactor may have its own molecular weight distributionand/or comonomer content distribution.

The first heterophasic propylene copolymer (HECO1) according to thisinvention is preferably produced in a sequential polymerization process,i.e. in a multistage process, known in the art, wherein the firstpropylene polymer (M1) is produced at least in one slurry reactor,preferably in a slurry reactor and optionally in a subsequent gas phasereactor, and subsequently the first elastomeric propylene copolymer (E1)is produced at least in one, i.e. one or two, gas phase reactor(s).

Accordingly it is preferred that the first heterophasic propylenecopolymer (HECO1) is produced in a sequential polymerization processcomprising the steps of

-   (a) polymerizing propylene and optionally at least one ethylene    and/or C₄ to C₁₂ α-olefin in a first reactor (R1) obtaining the    first polypropylene fraction of the first propylene polymer (M1),    preferably said first polypropylene fraction is a propylene    homopolymer,-   (b) transferring the first polypropylene fraction into a second    reactor (R2),-   (c) polymerizing in the second reactor (R2) and in the presence of    said first polypropylene fraction propylene and optionally at least    one ethylene and/or C₄ to C₁₂ α-olefin obtaining thereby the second    polypropylene fraction, preferably said second polypropylene    fraction is a second propylene homopolymer, said first polypropylene    fraction and said second polypropylene fraction form the first    propylene polymer (M1), i.e. the matrix of the first heterophasic    propylene copolymer (HECO1),-   (d) transferring the first propylene polymer (M1) of step (c) into a    third reactor (R3),-   (e) polymerizing in the third reactor (R3) and in the presence of    the first propylene polymer (M1) obtained in step (c) propylene and    ethylene to obtain the first elastomeric propylene copolymer (E1)    dispersed in the first propylene polymer (M1), the first propylene    polymer (M1) and the first elastomeric propylene copolymer (E1) form    the first heterophasic propylene copolymer (HECO1).

Of course, in the first reactor (R1) the second polypropylene fractioncan be produced and in the second reactor (R2) the first polypropylenefraction can be obtained. The same holds true for the elastomericpropylene copolymer phase.

Preferably between the second reactor (R2) and the third reactor (R3)the monomers are flashed out.

The term “sequential polymerization process” indicates that the firstheterophasic propylene copolymer (HECO1) is produced in at least two,like three or four reactors connected in series. Accordingly, thepresent process comprises at least a first reactor (R1) and a secondreactor (R2), more preferably a first reactor (R1), a second reactor(R2), and a third reactor (R3). The term “polymerization reactor” shallindicate that the main polymerization takes place. Thus in case theprocess consists of four polymerization reactors, this definition doesnot exclude the option that the overall process comprises for instance apre-polymerization step in a pre-polymerization reactor. The term“consist of” is only a closing formulation in view of the mainpolymerization reactors.

The first reactor (R1) is preferably a slurry reactor (SR) and can beany continuous or simple stirred batch tank reactor or loop reactoroperating in bulk or slurry. Bulk means a polymerization in a reactionmedium that comprises of at least 60% (w/w) monomer. According to thepresent invention the slurry reactor (SR) is preferably a (bulk) loopreactor (LR).

The second reactor (R2) can be a slurry reactor, like a loop reactor, asthe first reactor or alternatively a gas phase reactor (GPR).

The third reactor (R3) is preferably a gas phase reactor (GPR).

Such gas phase reactors (GPR) can be any mechanically mixed or fluid bedreactors. Preferably the gas phase reactors (GPR) comprise amechanically agitated fluid bed reactor with gas velocities of at least0.2 m/sec. Thus it is appreciated that the gas phase reactor is afluidized bed type reactor preferably with a mechanical stirrer.

Thus in a preferred embodiment the first reactor (R1) is a slurryreactor (SR), like a loop reactor (LR), whereas the second reactor (R2)and the third reactor (R3) are gas phase reactors (GPR). Accordingly forthe instant process at least three, preferably three polymerizationreactors, namely a slurry reactor (SR), like a loop reactor (LR), afirst gas phase reactor (GPR-1) and a second gas phase reactor (GPR-2)connected in series are used. If needed prior to the slurry reactor (SR)a pre-polymerization reactor is placed.

In another preferred embodiment the first reactor (R1) and secondreactor (R2) are slurry reactors (SR), like a loop reactors (LR),whereas the third reactor (R3) is a gas phase reactors (GPR).Accordingly for the instant process at least three, preferably threepolymerization reactors, namely two slurry reactors (SR), like two loopreactors (LR), and a gas phase reactor (GPR-1) connected in series areused. If needed prior to the first slurry reactor (SR) apre-polymerization reactor is placed.

A preferred multistage process is a “loop-gas phase”-process, such asdeveloped by Borealis A/S, Denmark (known as BORSTAR® technology)described e.g. in patent literature, such as in EP 0 887 379, WO92/12182 WO 2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 or inWO 00/68315.

A further suitable slurry-gas phase process is the Spheripol® process ofBasell.

Preferably, in the instant process for producing the first heterophasicpropylene copolymer (HECO1) as defined above the conditions for thefirst reactor (R1), i.e. the slurry reactor (SR), like a loop reactor(LR), of step (a) may be as follows:

-   -   the temperature is within the range of 50° C. to 110° C.,        preferably between 60° C. and 100° C., more preferably between        68 and 95° C.,    -   the pressure is within the range of 20 bar to 80 bar, preferably        between 40 bar to 70 bar,    -   hydrogen can be added for controlling the molar mass in a manner        known per se.

Subsequently, the reaction mixture from step (a) is transferred to thesecond reactor (R2), i.e. gas phase reactor (GPR-1), i.e. to step (c),whereby the conditions in step (c) are preferably as follows:

-   -   the temperature is within the range of 50° C. to 130° C.,        preferably between 60° C. and 100° C.,    -   the pressure is within the range of 5 bar to 50 bar, preferably        between 15 bar to 35 bar,    -   hydrogen can be added for controlling the molar mass in a manner        known per se.

The condition in the third reactor (R3), preferably in the second gasphase reactor (GPR-2) is similar to the second reactor (R2).

The residence time can vary in the three reactor zones.

In one embodiment of the process for producing the polypropylene theresidence time in bulk reactor, e.g. loop is in the range 0.1 to 2.5hours, e.g. 0.15 to 1.5 hours and the residence time in gas phasereactor will generally be 0.2 to 6.0 hours, like 0.5 to 4.0 hours.

If desired, the polymerization may be effected in a known manner undersupercritical conditions in the first reactor (R1), i.e. in the slurryreactor (SR), like in the loop reactor (LR), and/or as a condensed modein the gas phase reactors (GPR).

Preferably the process comprises also a prepolymerization with thecatalyst system, as described in detail below, comprising aZiegler-Natta procatalyst, an external donor and optionally acocatalyst.

In a preferred embodiment, the prepolymerization is conducted as bulkslurry polymerization in liquid propylene, i.e. the liquid phase mainlycomprises propylene, with minor amount of other reactants and optionallyinert components dissolved therein.

The prepolymerization reaction is typically conducted at a temperatureof 10 to 60° C., preferably from 15 to 50° C., and more preferably from20 to 45° C.

The pressure in the prepolymerization reactor is not critical but mustbe sufficiently high to maintain the reaction mixture in liquid phase.Thus, the pressure may be from 20 to 100 bar, for example 30 to 70 bar.

The catalyst components are preferably all introduced to theprepolymerization step. However, where the solid catalyst component (i)and the cocatalyst (ii) can be fed separately it is possible that only apart of the cocatalyst is introduced into the prepolymerization stageand the remaining part into subsequent polymerization stages. Also insuch cases it is necessary to introduce so much cocatalyst into theprepolymerization stage that a sufficient polymerization reaction isobtained therein.

It is possible to add other components also to the prepolymerizationstage. Thus, hydrogen may be added into the prepolymerization stage tocontrol the molecular weight of the prepolymer as is known in the art.Further, antistatic additive may be used to prevent the particles fromadhering to each other or to the walls of the reactor.

The precise control of the prepolymerization conditions and reactionparameters is within the skill of the art.

According to the invention the heterophasic composition (HECO1) isobtained by a multistage polymerization process, as described above, inthe presence of a catalyst system comprising as component (i) aZiegler-Natta procatalyst which contains a trans-esterification productof a lower alcohol and a phthalic ester.

The procatalyst used according to the invention for preparing theheterophasic composition (HECO1) is prepared by

a) reacting a spray crystallized or emulsion solidified adduct of MgCl₂and a C₁-C₂ alcohol with TiCl₄b) reacting the product of stage a) with a dialkylphthalate of formula(I)

-   -   wherein R^(1′) and R^(2′) are independently at least a C₅ alkyl        under conditions where a transesterification between said C₁ to        C₂ alcohol and said dialkylphthalate of formula (I) takes place        to form the internal donor        c) washing the product of stage b) or        d) optionally reacting the product of step c) with additional        TiCl₄

The procatalyst is produced as defined for example in the patentapplications WO 87/07620, WO 92/19653, WO 92/19658 and EP 0 491 566. Thecontent of these documents is herein included by reference.

First an adduct of MgCl₂ and a C₁-C₂ alcohol of the formula MgCl₂*nROH,wherein R is methyl or ethyl and n is 1 to 6, is formed. Ethanol ispreferably used as alcohol.

The adduct, which is first melted and then spray crystallized oremulsion solidified, is used as catalyst carrier.

In the next step the spray crystallized or emulsion solidified adduct ofthe formula MgCl₂*nROH, wherein R is methyl or ethyl, preferably ethyland n is 1 to 6, is contacting with TiCl₄ to form a titanized carrier,followed by the steps of

-   -   adding to said titanised carrier    -   (i) a dialkylphthalate of formula (I) with R^(1′) and R^(2′)        being independently at least a C₈-alkyl, like at least a        C₈-alkyl,    -   or preferably    -   (ii) a dialkylphthalate of formula (I) with R^(1′) and R^(2′)        being the same and being at least a C₈-alkyl, like at least a        C₈-alkyl,    -   or more preferably    -   (iii) a dialkylphthalate of formula (I) selected from the group        consisting of propylhexylphthalate (PrHP), dioctylphthalate        (DOP), di-iso-decylphthalate (DIDP), and ditridecylphthalate        (DTDP), yet more preferably the dialkylphthalate of formula (I)        is a dioctylphthalate (DOP), like di-iso-octylphthalate or        diethylhexylphthalate, in particular diethylhexylphthalate,    -   to form a first product,    -   subjecting said first product to suitable transesterification        conditions, i.e. to a temperature above 100° C., preferably        between 100 to 150° C., more preferably between 130 to 150° C.,        such that said methanol or ethanol is transesterified with said        ester groups of said dialkylphthalate of formula (I) to form        preferably at least 80 mol-%, more preferably 90 mol-%, most        preferably 95 mol.-%, of a dialkylphthalate of formula (II)

-   -   with R¹ and R² being methyl or ethyl, preferably ethyl, the        dialkylphthalat of formula (II) being the internal donor and    -   recovering said transesterification product as the procatalyst        composition (component (i)).

The adduct of the formula MgCl₂*nROH, wherein R is methyl or ethyl and nis 1 to 6, is in a preferred embodiment melted and then the melt ispreferably injected by a gas into a cooled solvent or a cooled gas,whereby the adduct is crystallized into a morphologically advantageousform, as for example described in WO 87/07620.

This crystallized adduct is preferably used as the catalyst carrier andreacted to the procatalyst useful in the present invention as describedin WO 92/19658 and WO 92/19653.

As the catalyst residue is removed by extracting, an adduct of thetitanised carrier and the internal donor is obtained, in which the groupderiving from the ester alcohol has changed.

In case sufficient titanium remains on the carrier, it will act as anactive element of the procatalyst.

Otherwise the titanization is repeated after the above treatment inorder to ensure a sufficient titanium concentration and thus activity.

Preferably the procatalyst used according to the invention contains 2.5wt.-% of titanium at the most, preferably 2.2% wt.-% at the most andmore preferably 2.0 wt.-% at the most. Its donor content is preferablybetween 4 to 12 wt.-% and more preferably between 6 and 10 wt.-%.

More preferably the procatalyst used according to the invention has beenproduced by using ethanol as the alcohol and dioctylphthalate (DOP) asdialkylphthalate of formula (I), yielding diethyl phthalate (DEP) as theinternal donor compound.

Still more preferably the catalyst used according to the invention isthe catalyst as described in the example section; especially with theuse of dioctylphthalate as dialkylphthalate of formula (I).

For the production of the heterophasic composition (HECO1) according tothe invention the catalyst system used preferably comprises in additionto the special Ziegler-Natta procatalyst an organometallic cocatalyst ascomponent (ii).

Accordingly it is preferred to select the cocatalyst from the groupconsisting of trialkylaluminium, like triethylaluminium (TEA), dialkylaluminium chloride and alkyl aluminium sesquichloride.

Component (iii) of the catalysts system used is an external donorrepresented by formula (IIIa) or (IIIb). Formula (IIIa) is defined by

Si(OCH₃)₂R₂ ⁵  (IIIa)

wherein R⁵ represents a branched-alkyl group having 3 to 12 carbonatoms, preferably a branched-alkyl group having 3 to 6 carbon atoms, ora cyclo-alkyl having 4 to 12 carbon atoms, preferably a cyclo-alkylhaving 5 to 8 carbon atoms.

It is in particular preferred that R⁵ is selected from the groupconsisting of iso-propyl, iso-butyl, iso-pentyl, tert.-butyl,tert.-amyl, neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl andcycloheptyl.

Formula (IIIb) is defined by

Si(OCH₂CH₃)₃(NR^(x)R^(y))  (IIIb)

wherein R^(x) and R^(y) can be the same or different a represent ahydrocarbon group having 1 to 12 carbon atoms.

R^(x) and R^(y) are independently selected from the group consisting oflinear aliphatic hydrocarbon group having 1 to 12 carbon atoms, branchedaliphatic hydrocarbon group having 1 to 12 carbon atoms and cyclicaliphatic hydrocarbon group having 1 to 12 carbon atoms. It is inparticular preferred that R^(x) and R^(y) are independently selectedfrom the group consisting of methyl, ethyl, n-propyl, n-butyl, octyl,decanyl, iso-propyl, iso-butyl, iso-pentyl, tert.-butyl, tert.-amyl,neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl and cycloheptyl.

More preferably both R^(x) and R^(y) are the same, yet more preferablyboth R^(x) and R^(y) are an ethyl group.

More preferably the external donor is of formula (IIIa), likedicyclopentyl dimethoxy silane [Si(OCH₃)₂(cyclo-pentyl)₂], diisopropyldimethoxy silane [Si(OCH₃)₂(CH(CH₃)₂)₂].

Most preferably the external donor is dicyclopentyl dimethoxy silane[Si(OCH₃)₂(cyclo-pentyl)₂].

In a further embodiment, the Ziegler-Natta procatalyst can be modifiedby polymerising a vinyl compound in the presence of the catalyst system,comprising the special Ziegler-Natta procatalyst (component (i)), anexternal donor (component (iii) and optionally a cocatalyst (component(iii)), which vinyl compound has the formula:

CH₂═CH—CHR³R⁴

wherein R³ and R⁴ together form a 5- or 6-membered saturated,unsaturated or aromatic ring or independently represent an alkyl groupcomprising 1 to 4 carbon atoms, and the modified catalyst is used forthe preparation of the heterophasic composition (HECO) according to thisinvention. The polymerized vinyl compound can act as an α-nucleatingagent.

Concerning the modification of catalyst reference is made to theinternational applications WO 99/24478, WO 99/24479 and particularly WO00/68315, incorporated herein by reference with respect to the reactionconditions concerning the modification of the catalyst as well as withrespect to the polymerization reaction.

The Second Heterophasic Propylene Copolymer (HECO2)

The inventive polypropylene composition (C) further comprises a secondheterophasic propylene copolymer (HECO2).

The second heterophasic propylene copolymer (HECO2) according to thisinvention comprises a matrix (M) being the second propylene polymer (M2)and dispersed therein an elastomeric propylene copolymer (E) being thesecond elastomeric propylene copolymer (E2). Thus the matrix (M)contains (finely) dispersed inclusions being not part of the matrix (M)and said inclusions contain the elastomeric propylene copolymer (E).Regarding the term inclusion, reference is made to the definitionprovided above.

Accordingly, the second heterophasic composition (HECO2) according tothis invention preferably comprises

(a) the (semi)crystalline second propylene polymer (M2) as the matrix(M) and(b) the second elastomeric propylene copolymer (E2).

Preferably the weight ratio between the second propylene polymer (M2)and the elastomeric propylene copolymer (E2) [M2/E2] of the secondheterophasic propylene copolymer (HECO2) is in the range of 90/10 to40/60, more preferably in the range of 85/15 to 45/55, yet morepreferably in the range of 83/17 to 50/50, like in the range of 75/25 to60/40.

Preferably, the second heterophasic propylene copolymer (HECO2)according to this invention comprises as polymer components only thesecond propylene polymer (M2) and the first elastomeric propylenecopolymer (E2). In other words, the second heterophasic propylenecopolymer (HECO2) may contain further additives but no other polymer inan amount exceeding 5.0 wt.-%, more preferably exceeding 3.0 wt.-%, likeexceeding 1.0 wt.-%, based on the total second heterophasic propylenecopolymer (HECO2). One additional polymer which may be present in suchlow amounts is a polyethylene which is a reaction by-product obtained bythe preparation of the second heterophasic propylene copolymer (HECO2).Accordingly, it is in particular appreciated that the instant secondheterophasic propylene copolymer (HECO2) contains only the secondpropylene polymer (M2), the second elastomeric propylene copolymer (E2)and optionally polyethylene in amounts as mentioned in this paragraph.

The second heterophasic propylene copolymer (HECO2) applied according tothis invention is featured by a rather low melt flow rate. Accordingly,the second heterophasic propylene copolymer (HECO2) has a melt flow rateMFR₂ (230° C.) in the range of 1.0 to 20 g/10 min, preferably in therange of 3.0 to 15 g/10 min, more preferably in the range of 5.0 to 10g/10 min.

Preferably, it is desired that the second heterophasic propylenecopolymer (HECO2) is thermo mechanically stable. Accordingly, it isappreciated that the second heterophasic propylene copolymer (HECO2) hasa melting temperature of at least 162° C., more preferably in the rangeof 163 to 167° C., still more preferably in the range of 163 to 165° C.

The second heterophasic propylene copolymer (HECO2) comprises apart frompropylene also comonomers. Preferably the second heterophasic propylenecopolymer (HECO2) comprises apart from propylene ethylene and/or C₄ toC₈ α-olefins. Regarding term “propylene copolymer”, reference is made tothe definition provided above.

Thus, the second heterophasic propylene copolymer (HECO2), i.e. secondpropylene polymer (M2) as well as the second elastomeric propylenecopolymer (E2), can comprise monomers copolymerizable with propylene,for example comonomers such as ethylene and/or C₄ to C₈ α-olefins, inparticular ethylene and/or C₄ to C₈ α-olefins, e.g. 1-butene and/or1-hexene. Preferably, the second heterophasic propylene copolymer(HECO2) according to this invention comprises, especially consists of,monomers copolymerizable with propylene from the group consisting ofethylene, 1-butene and 1-hexene. More specifically, the secondheterophasic propylene copolymer (HECO2) of this inventioncomprises—apart from propylene—units derivable from ethylene and/or1-butene. In a preferred embodiment, the second heterophasic propylenecopolymer (HECO2) according to this invention comprises units derivablefrom ethylene and propylene only. Still more preferably the secondpropylene polymer (M1) as well as the second elastomeric propylenecopolymer (E2) of the second heterophasic propylene copolymer (HECO2)contain the same comonomers, like ethylene.

Additionally, it is appreciated that the second heterophasic propylenecopolymer (HECO2) preferably has a rather low total comonomer content,preferably ethylene content. Thus, it is preferred that the comonomercontent of the second heterophasic propylene copolymer (HECO2) is in therange from 5.0 to 30.0 mol-%, preferably in the range from 6.0 to 18.0mol-%, more preferably in the range from 7.0 to 13.0 mol-%.

The xylene cold soluble (XCS) fraction measured according to accordingISO 16152 (25° C.) of the second heterophasic propylene copolymer(HECO2) is in the range of 15.0 to 40.0 wt.-%, preferably in the rangefrom 17.0 to 35.0 wt.-%, more preferably in the range from 20.0 to 33.0wt.-%, still more preferably in the range from 23.0 to 30.0 wt.-%.

Further it is appreciated that the xylene cold soluble (XCS) fraction ofthe second heterophasic propylene copolymer (HECO2) is specified by itsintrinsic viscosity. A low intrinsic viscosity (IV) value reflects a lowweight average molecular weight. For the present invention it isappreciated that the xylene cold soluble fraction (XCS) of the secondheterophasic propylene copolymer (HECO2) has an intrinsic viscosity (IV)measured according to ISO 1628/1 (at 135° C. in decalin) above 3.5 dl/g.More preferably, the second heterophasic propylene copolymer (HECO2) hasan intrinsic viscosity (IV) in the range of 3.5 to 9.0 dl/g, preferablyin the range of 3.7 to 8.5 dl/g, more preferably in the range of 3.9.0to 8.0 dl/g.

Additionally, it is preferred that the comonomer content, i.e. ethylenecontent, of the xylene cold soluble (XCS) fraction of the secondheterophasic propylene copolymer (HECO2) is below 39 mol-%, preferablyin the range of 20 to 38 mol-%, more preferably in the range of 23 to 35mol.-%, yet more preferably in the range of 25 to 29 mol.-%. Thecomonomers present in the xylene cold soluble (XCS) fraction are thosedefined above for the second propylene polymer (M2) and the secondelastomeric propylene copolymer (E2), respectively. In one preferredembodiment the comonomer is ethylene only.

The second heterophasic propylene copolymer (HECO2) can be furtherdefined by its individual components, i.e. the second propylene polymer(M2) and the second elastomeric propylene copolymer (E2).

The second propylene polymer (M2) can be a propylene copolymer or apropylene homopolymer, the latter being preferred.

In case the second propylene polymer (M2) is a propylene copolymer, thesecond propylene polymer (M2) comprises monomers copolymerizable withpropylene, for example comonomers such as ethylene and/or C₄ to C₈α-olefins, in particular ethylene and/or C₄ to C₆ α-olefins, e.g.1-butene and/or 1-hexene. Preferably the second propylene polymer (M2)according to this invention comprises, especially consists of, monomerscopolymerizable with propylene from the group consisting of ethylene,1-butene and 1-hexene. More specifically the second propylene polymer(M2) of this invention comprises—apart from propylene—units derivablefrom ethylene and/or 1-butene. In a preferred embodiment the secondpropylene polymer (M2) comprises units derivable from ethylene andpropylene only.

The second propylene polymer (M2) according to this invention has a meltflow rate MFR₂ (230° C./2.16 kg) measured according to ISO 1133 in therange of 70 to 300 g/10 min, more preferably in the range of 75 to 250g/10 min, still more preferably in the range of 80 to 200 g/10 min

As mentioned above the second heterophasic propylene copolymer (HECO2)is featured by a low comonomer content. Accordingly, the comonomercontent of the second propylene polymer (M2) is in the range of 0.0 to5.0 mol-%, yet more preferably in the range of 0.0 to 3.0 mol-%, stillmore preferably in the range of 0.0 to 1.0 mol-%. It is especiallypreferred that the second propylene polymer (M2) is a propylenehomopolymer.

The second propylene polymer (M2) preferably comprises at least twopolymer fractions, like two or three polymer fractions, all of them arepropylene homopolymers. Even more preferred the second propylene polymer(M2) comprises, preferably consists of, a first propylene homopolymerfraction (H-PP1) and a second propylene homopolymer fraction (H-PP2).

Preferably, the first propylene homopolymer fraction (H-PP1) and thesecond propylene homopolymer fraction (H-PP2) differ in melt flow rate.

Accordingly, one of the propylene homopolymer fractions (H-PP1) and(H-PP2) of the second propylene polymer (M2) is the low melt flow rateMFR₂ (230° C./2.16 kg) fraction and the other fraction is the high meltflow rate MFR₂ (230° C./2.16 kg) fraction, wherein further the low flowfraction and the high flow fraction fulfil in equation (I), morepreferably in equation (Ia), still more preferably in equation (Ib),

$\begin{matrix}{{\frac{{MFR}({high})}{{MFR}({low})} \geq 2.0},} & (I) \\{{8.0 \geq \frac{{MFR}({high})}{{MFR}({low})} \geq 2.5},} & ({Ia}) \\{{5.0 \geq \frac{{MFR}({high})}{{MFR}({low})} \geq 3.5},} & ({Ib})\end{matrix}$

wherein MFR (high) is the melt flow rate MFR₂ (230° C./2.16 kg) [g/10min] of the propylene homopolymer fraction with the higher melt flowrate MFR₂ (230° C./2.16 kg) and MFR (low) is the melt flow rate MFR₂(230° C./2.16 kg) [g/10 min] of the propylene homopolymer fraction withthe lower melt flow rate MFR₂ (230° C./2.16 kg).

Preferably, the first propylene copolymer fraction (H-PP1) is the randomcopolymer fraction with the higher melt flow rate MFR₂ (230° C./2.16 kg)and the second propylene copolymer fraction (H-PP2) is the randomcopolymer fraction with the lower melt flow rate MFR₂ (230° C./2.16 kg).

Accordingly, it is preferred that the first propylene homopolymerfraction (H-PP1) has a melt flow rate MFR₂ (230° C./2.16 kg) in therange of 90 to 160 g/10 min, more preferably in the range of 100 to 150g/10 min, still more preferably in the range of 120 to 140 g/10 minand/or that the second propylene copolymer fraction (EC2) has a meltflow rate MFR₂ (230° C./2.16 kg) in the range of 10 to 39 g/10 min, morepreferably in the range of 17 to 32 g/10 min, still more preferably inthe range of 22 to 27 g/10 min.

Further, the weight ratio between the first propylene homopolymerfraction (H-PP1) and second propylene homopolymer fraction (H-PP2)preferably is 20:80 to 80:20, more preferably 75:25 to 25:75, still morepreferably 55:45 to 45:55.

The second heterophasic propylene copolymer (HECO2) preferably comprises60 to 95 wt.-%, more preferably 70 to 90 wt.-%, still more preferably 72to 87 wt.-% of the second propylene polymer (M2), based on the totalweight of the second heterophasic propylene copolymer (HECO2).

Additionally, the second heterophasic propylene copolymer (HECO2)preferably comprises 5 to 40 wt.-%, more preferably 10 to 30 wt.-%,still more preferably 13 to 28 wt.-% of the second elastomeric propylenecopolymer (E2), based on the total weight of the second heterophasicpropylene copolymer (HECO2).

Thus, it is appreciated that the second heterophasic propylene copolymer(HECO2) preferably comprises, more preferably consists of, 60 to 95wt.-%, more preferably 70 to 90 wt.-%, still more preferably 72 to 87wt.-% of the second propylene polymer (M2) and 5 to 40 wt.-%, morepreferably 10 to 30 wt.-%, still more preferably 13 to 28 wt.-% of thesecond elastomeric propylene copolymer (E2), based on the total weightof the second heterophasic propylene copolymer (HECO2).

Accordingly, a further component of the second heterophasic propylenecopolymer (HECO2) is the second elastomeric propylene copolymer (E2)dispersed in the matrix (M) being the second propylene polymer (M2).Concerning the comonomers used in the second elastomeric propylenecopolymer (E2) it is referred to the information provided for the firstheterophasic propylene copolymer (HECO1). Accordingly, the secondelastomeric propylene copolymer (E2) comprises monomers copolymerizablewith propylene, for example comonomers such as ethylene and/or C₄ to C₈α-olefins, in particular ethylene and/or C₄ to C₆ α-olefins, e.g.1-butene and/or 1-hexene. Preferably, the second elastomeric propylenecopolymer (E2) comprises, especially consists of, monomerscopolymerizable with propylene from the group consisting of ethylene,1-butene and 1-hexene. More specifically, the second elastomericpropylene copolymer (E2) comprises—apart from propylene—units derivablefrom ethylene and/or 1-butene. Thus, in an especially preferredembodiment the second elastomeric propylene copolymer (E2) comprisesunits derivable from ethylene and propylene only.

The comonomer content of the second elastomeric propylene copolymer (E2)preferably is in the range of 15.0 to 55.0 mol-%, more preferably in therange of 20.0 to 50.0 mol-%, still more preferably in the range of 25.0to 40.0 mol-%.

The second heterophasic propylene copolymer (HECO2) as defined in theinstant invention may contain up to 5.0 wt.-% additives, like nucleatingagents and antioxidants, as well as slip agents and antiblocking agents.Preferably the additive content (without α-nucleating agents) is below3.0 wt.-%, like below 1.0 wt.-%.

According to a preferred embodiment of the present invention, the secondheterophasic propylene copolymer (HECO2) contains an α-nucleating agent.

Regarding the preferred α-nucleating agents, reference is made to theα-nucleating agents described above with regard to the firstheterophasic propylene copolymer (HECO1).

The second heterophasic propylene copolymer (HECO2) can be produced byblending the second propylene polymer (M2) and the second elastomericpropylene copolymer (E2). However, it is preferred that the secondheterophasic propylene copolymer (HECO2) is produced in a sequentialstep process, using reactors in serial configuration and operating atdifferent reaction conditions. As a consequence, each fraction preparedin a specific reactor may have its own molecular weight distributionand/or comonomer content distribution.

Accordingly, it is preferred that the second heterophasic propylenecopolymer (HECO2) is produced in a sequential polymerization processcomprising the steps of

-   (a) polymerizing propylene and optionally at least one ethylene    and/or C₄ to C₁₂ α-olefin in a first reactor (R₁) obtaining the    first polypropylene fraction of the first propylene polymer (M1),    preferably said first polypropylene fraction is a propylene    homopolymer,-   (b) transferring the first polypropylene fraction into a second    reactor (R₂),-   (c) polymerizing in the second reactor (R₂) and in the presence of    said first polypropylene fraction propylene and optionally at least    one ethylene and/or C₄ to C₁₂ α-olefin obtaining thereby the second    polypropylene fraction, preferably said second polypropylene    fraction is a second propylene homopolymer, said first polypropylene    fraction and said second polypropylene fraction form the second    propylene polymer (M2), i.e. the matrix of the second heterophasic    propylene copolymer (HECO2),-   (d) transferring the second propylene polymer (M2) of step (c) into    a third reactor (R₃),-   (e) polymerizing in the third reactor (R₃) and in the presence of    the second propylene polymer (M2) obtained in step (c) propylene and    ethylene to obtain the first propylene copolymer fraction of the    second elastomeric propylene copolymer (E2) dispersed in the second    propylene polymer (M2),-   (f) transferring the second propylene polymer (M2) and the first    propylene copolymer fraction of the second elastomeric propylene    copolymer (E2) into a fourth reactor (R₄),-   (g) polymerizing in the fourth reactor (R₄) and in the presence of    the second propylene polymer (M2) and the first propylene copolymer    fraction of the second elastomeric propylene copolymer (E2)    propylene and ethylene to obtain the second propylene copolymer    fraction of the second elastomeric propylene copolymer (E2)    dispersed in the second propylene polymer (M2), the second propylene    polymer (M2) and the second elastomeric propylene copolymer (E) form    the second propylene copolymer (HECO2).

Of course, in the first reactor (R₁) the second polypropylene fractioncan be produced and in the second reactor (R₂) the first polypropylenefraction can be obtained. The same holds true for the elastomericpropylene copolymer phase.

Preferably between the second reactor (R₂) and the third reactor (R₃)the monomers are flashed out.

The term “sequential polymerization process” indicates that the secondheterophasic propylene copolymer (HECO2) is produced in at least two,like three or four reactors connected in series. Accordingly, thepresent process comprises at least a first reactor (R₁) and a secondreactor (R₂), more preferably a first reactor (R₁), a second reactor(R₂), a third reactor (R₃) and a fourth reactor (R₄). Regarding the term“polymerization reactor”, reference is made to the definition providedabove.

The first reactor (R₁) is preferably a slurry reactor (SR) and can beany continuous or simple stirred batch tank reactor or loop reactoroperating in bulk or slurry. Bulk means a polymerization in a reactionmedium that comprises of at least 60% (w/w) monomer.

According to the present invention the slurry reactor (SR) is preferablya (bulk) loop reactor (LR).

The second reactor (R₂) can be a slurry reactor, like a loop reactor, asthe first reactor or alternatively a gas phase reactor (GPR).

The third reactor (R₃) and the fourth reactor (R₄) are preferably gasphase reactors (GPR).

Such gas phase reactors (GPR) can be any mechanically mixed or fluid bedreactors. Preferably the gas phase reactors (GPR) comprise amechanically agitated fluid bed reactor with gas velocities of at least0.2 m/sec. Thus it is appreciated that the gas phase reactor is afluidized bed type reactor preferably with a mechanical stirrer.

Thus in a preferred embodiment the first reactor (R₁) is a slurryreactor (SR), like a loop reactor (LR), whereas the second reactor (R₂),the third reactor (R₃) and the fourth reactor (R₄) are gas phasereactors (GPR). Accordingly for the instant process at least four,preferably four polymerization reactors, namely a slurry reactor (SR),like a loop reactor (LR), a first gas phase reactor (GPR-1), a secondgas phase reactor (GPR-2) and a third gas phase ractor (GPR-3) connectedin series are used. If needed prior to the slurry reactor (SR) apre-polymerization reactor is placed.

In another preferred embodiment the first reactor (R₁) and secondreactor (R₂) are slurry reactors (SR), like a loop reactors (LR),whereas the third reactor (R₃) and the fourth reactor (R₄) are gas phasereactors (GPR). Accordingly for the instant process at least three,preferably three polymerization reactors, namely two slurry reactors(SR), like two loop reactors (LR), and two gas phase reactors (GPR-1)and (GPR-2) connected in series are used. If needed prior to the firstslurry reactor (SR) a pre-polymerization reactor is placed.

A preferred multistage process is a “loop-gas phase”-process, such asdeveloped by Borealis A/S, Denmark (known as BORSTAR® technology)described e.g. in patent literature, such as in EP 0 887 379, WO92/12182 WO 2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 or inWO 00/68315.

A further suitable slurry-gas phase process is the Spheripol® process ofBasell.

Preferably, in the instant process for producing the second heterophasicpropylene copolymer (HECO2) as defined above the conditions for thefirst reactor (R₁), i.e. the slurry reactor (SR), like a loop reactor(LR), of step (a) may be as follows:

-   -   the temperature is within the range of 50° C. to 110° C.,        preferably between 60° C. and 100° C., more preferably between        68 and 95° C.,    -   the pressure is within the range of 20 bar to 80 bar, preferably        between 40 bar to 70 bar,    -   hydrogen can be added for controlling the molar mass in a manner        known per se.

Subsequently, the reaction mixture from step (a) is transferred to thesecond reactor (R₂), i.e. gas phase reactor (GPR-1), i.e. to step (c),whereby the conditions in step (c) are preferably as follows:

-   -   the temperature is within the range of 50° C. to 130° C.,        preferably between 60° C. and 100° C.,    -   the pressure is within the range of 5 bar to 50 bar, preferably        between 15 bar to 35 bar,    -   hydrogen can be added for controlling the molar mass in a manner        known per se.

The residence time can vary in the three reactor zones.

In one embodiment of the process for producing the polypropylene theresidence time in bulk reactor, e.g. loop is in the range 0.1 to 2.5hours, e.g. 0.15 to 1.5 hours and the residence time in gas phasereactor will generally be 0.2 to 6.0 hours, like 0.5 to 4.0 hours.

If desired, the polymerization may be effected in a known manner undersupercritical conditions in the first reactor (R₁), i.e. in the slurryreactor (SR), like in the loop reactor (LR), and/or as a condensed modein the gas phase reactors (GPR).

Preferably the process comprises also a prepolymerization with thecatalyst system, as described in detail below, comprising aZiegler-Natta procatalyst, an external donor and optionally acocatalyst.

In a preferred embodiment, the prepolymerization is conducted as bulkslurry polymerization in liquid propylene, i.e. the liquid phase mainlycomprises propylene, with minor amount of other reactants and optionallyinert components dissolved therein.

The prepolymerization reaction is typically conducted at a temperatureof 10 to 60° C., preferably from 15 to 50° C., and more preferably from20 to 45° C.

The pressure in the prepolymerization reactor is not critical but mustbe sufficiently high to maintain the reaction mixture in liquid phase.Thus, the pressure may be from 20 to 100 bar, for example 30 to 70 bar.

The catalyst components are preferably all introduced to theprepolymerization step. However, where the solid catalyst component (i)and the cocatalyst (ii) can be fed separately it is possible that only apart of the cocatalyst is introduced into the prepolymerization stageand the remaining part into subsequent polymerization stages. Also insuch cases it is necessary to introduce so much cocatalyst into theprepolymerization stage that a sufficient polymerization reaction isobtained therein.

It is possible to add other components also to the prepolymerizationstage. Thus, hydrogen may be added into the prepolymerization stage tocontrol the molecular weight of the prepolymer as is known in the art.Further, antistatic additive may be used to prevent the particles fromadhering to each other or to the walls of the reactor.

The precise control of the prepolymerization conditions and reactionparameters is within the skill of the art.

According to the invention the second heterophasic propylene copolymer(HECO2) is obtained by a multistage polymerization process, as describedabove, in the presence of a catalyst system comprising as component (i)a Ziegler-Natta procatalyst which contains a trans-esterificationproduct of a lower alcohol and a phthalic ester.

Regarding the preferred catalyst system, reference is made to thecatalyst defined above with regard to the first heterophasic propylenecopolymer (HECO1).

In a further embodiment, the Ziegler-Natta procatalyst for theproduction of the second heterophasic propylene copolymer (HECO2) canalso be modified by polymerizing a vinyl compound in the presence of thecatalyst system as described above.

The Plastomer (PL)

According to a preferred embodiment of the present invention, thepolypropylene composition (C) further comprises a plastomer (PL) being acopolymer of ethylene and a C₄ to C₈ α-olefin.

The plastomer (PL) can be any elastomeric polyolefin with the provisothat it chemically differs from the elastomeric propylene copolymers(E1) and (E2) as defined herein. More preferably the plastomer (PL) is avery low density polyolefin, still more preferably a very low densitypolyolefin polymerized using single site catalysis, preferablymetallocene catalysis. Typically, the plastomer (PL) is an ethylenecopolymer.

The plastomer (PL) has a density below 0.900 g/cm³. More preferably, thedensity of the plastomer (PL) is equal or below 0.890 g/cm³, still morepreferably in the range of 0.845 to 0.890 g/cm³.

Preferably, the plastomer (PL) has a melt flow rate MFR₂ (190° C., 2.16kg) of less than 50 g/10 min, more preferably from 10.0 to 40 g/10 min,still more preferably from 15.0 to 35 g/10 min, like a range from 25.0to 33.0 g/10 min

Preferably, the plastomer (PL) comprises units derived from ethylene anda C₄ to C₂₀ α-olefin.

The plastomer (PL) comprises, preferably consists of, units derivablefrom (i) ethylene and (ii) at least another C₄ to C₂₀ α-olefin, like C₄to C₁₀ α-olefin, more preferably units derivable from (i) ethylene and(ii) at least another α-olefin selected form the group consisting of1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene. It is especiallypreferred that the plastomer (PL) comprises at least units derivablefrom (i) ethylene and (ii) 1-butene or 1-octene. It is especiallypreferred that the plastomer (PL) is a copolymer of ethylene and1-octene.

In an especially preferred embodiment, the plastomer (PL) consists ofunits derivable from ethylene and 1-octene.

The comonomer content, like the C₄ to C₂₀ α-olefin content, of theplastomer (PL) is in the range of 3.0 to 25.0 mol-%, more preferably inthe range of 4.0 to 20.0 mol-%, still more preferably in the range of5.0 to 15.0 mol-%, like in the range of 6.0 to 10.0 mol-%.

In one preferred embodiment the plastomer (PL) is prepared with at leastone metallocene catalyst. The plastomer (PL) may also be prepared withmore than one metallocene catalyst or may be a blend of multipleelastomers prepared with different metallocene catalysts. In someembodiments, the plastomer (PL) is a substantially linear ethylenepolymer (SLEP). SLEPs and other metallocene catalysed plastomers (PL)are known in the art, for example, U.S. Pat. No. 5,272,236. These resinsare also commercially available, for example, as Queo™ plastomersavailable from Borealis, ENGAGE™ plastomer resins available from DowChemical Co. or EXACT™ polymers from Exxon or TAFMER™ polymers fromMitsui.

The High Density Polyethylene (HDPE)

According to a preferred embodiment of the present invention, thepolypropylene composition (C) further comprises a high densitypolyethylene (HDPE).

The expression “high density polyethylene” used in the instant inventionrelates to a polyethylene obtained in the presence of a Ziegler-Natta ormetallocene catalyst that consists substantially, i.e. of more than99.70 mol-%, still more preferably of at least 99.80 mol-%, of ethyleneunits. In a preferred embodiment only ethylene units in the high densitypolyethylene (HDPE) are detectable.

The high density polyethylene (HDPE) has a density of at least 0.800g/cm³. More preferably, the high density polyethylene (HDPE) has adensity in the range of 0.830 to 0.970 g/cm³, still more preferably inthe range of 0.900 to 0.965 g/cm³, like in the range of 0.940 to 0.960g/cm³.

It is especially preferred that the high density polyethylene (HDPE) hasa weight average molecular weight Mw in the range of 60 to 85 kg/mol,preferably in the range of 65 to 85 kg/mol, still more preferably in therange of 70 to 80 kg/mol.

Further it is preferred that the high density polyethylene (HDPE) has arather broad molecular weight distribution (Mw/Mn). Accordingly, it ispreferred that the molecular weight distribution (Mw/Mn) of the highdensity polyethylene (HDPE) is in the range of 6.0 to 8.0, morepreferably in the range of 6.5 to 7.5, like in the range of 6.5 to 7.0.

Additionally, it is preferred that the high density polyethylene (HDPE)has a rather high melt flow rate. Accordingly, the melt flow rate (190°C.) measured according to ISO 1133 of the high density polyethylene(HDPE) is preferably in the range of 20 to 40 g/10 min, more preferablyin the range of 25 to 35 g/10 min, still more preferably in the range of27 to 32 g/10 min at 190° C.

Preferably, the high density polyethylene (HDPE) according to thepresent invention is a high density polyethylene known in the art. Inparticular, it is preferred that the high density polyethylene (HDPE) isthe commercial ethylene homopolymer MG9641 of Borealis AG.

The Inorganic Filler (F)

A further requirement of the composition according to this invention isthe presence of an inorganic filler (F).

Preferably the inorganic filler (F) is a mineral filler. It isappreciated that the inorganic filler (F) is a phyllosilicate, mica orwollastonite. Even more preferred the inorganic filler (F) is selectedfrom the group consisting of mica, wollastonite, kaolinite, smectite,montmorillonite and talc.

The most preferred inorganic fillers (F) are talc and/or wollastonite.

It is appreciated that the filler (F) has median particle size (D₅₀) inthe range of 0.8 to 20 μM and a top cut particle size (D₉₅) in the rangeof 10 to 20 μm, preferably a median particle size (D₅₀) in the range of5.0 to 8.0 μm and top cut particle size (D₉₅) in the range of 12 to 17μm, more preferably a median particle size (D₅₀) in the range of 5.5 to7.8 μm and top cut particle size (D₉₅) of 13 to 16.5 μm.

According to this invention the filler (F) does not belong to the classof alpha nucleating agents and additives (AD).

The the filler (F) is state of the art and a commercially availableproduct.

Additives (AD)

In addition the first heterophasic propylene copolymer (HECO1), thesecond heterophasic propylene copolymer (HECO2), the inorganic filler(F), optionally the plastomer (PL) and optionally the high densitypolyethylene (HDPE), the composition (C) of the invention may includeadditives (AD). Typical additives are acid scavengers, antioxidants,colorants, light stabilisers, plasticizers, slip agents, anti-scratchagents, dispersing agents, processing aids, lubricants, pigments, andthe like. As indicated above the inorganic filler (F) is not regarded asan additive (AD).

Such additives are commercially available and for example described in“Plastic Additives Handbook”, 6^(th) edition 2009 of Hans Zweifel (pages1141 to 1190).

Furthermore, the term “additives (AD)” according to the presentinvention also includes carrier materials, in particular polymericcarrier materials.

The Polymeric Carrier Material

Preferably the composition (C) of the invention does not comprise (a)further polymer (s) different to the first and second heterophasicpropylene copolymers (HECO1) and (HECO2), the plastomer (PL) and thehigh density polyethylene (HDPE), in an amount exceeding 15 wt.-%,preferably in an amount exceeding 10 wt.-%, more preferably in an amountexceeding 9 wt.-%, based on the weight of the composition (C). Anypolymer being a carrier material for additives (AD) is not calculated tothe amount of polymeric compounds as indicated in the present invention,but to the amount of the respective additive.

The polymeric carrier material of the additives (AD) is a carrierpolymer to ensure a uniform distribution in the composition (C) of theinvention. The polymeric carrier material is not limited to a particularpolymer. The polymeric carrier material may be ethylene homopolymer,ethylene copolymer obtained from ethylene and α-olefin comonomer such asC₃ to C₈ α-olefin comonomer, propylene homopolymer and/or propylenecopolymer obtained from propylene and α-olefin comonomer such asethylene and/or C₄ to C₈ α-olefin comonomer.

The Article

The composition of the present invention is preferably used for theproduction of articles, more preferably of foamed articles. Even morepreferred is the use for the production of automotive articles,especially of car interiors and exteriors, like bumpers, side trims,step assists, body panels, spoilers, dashboards, interior trims and thelike.

The current invention also provides articles, more preferably foamedarticles, comprising, preferably comprising at least 60 wt.-%, morepreferably at least 80 wt.-%, yet more preferably at least 95 wt.-%,like consisting of, the inventive composition. Accordingly, the presentinvention is especially directed to parts of automotive articles,especially to car interiors and exteriors, like bumpers, side trims,step assists, body panels, spoilers, dashboards, interior trims and thelike, comprising, preferably comprising at least 60 wt.-%, morepreferably at least 80 wt.-%, yet more preferably at least 95 wt.-%,like consisting of, the inventive composition.

The Use

The present invention is also directed to the use of the inventivecomposition for the production of a foamed article as described in theprevious paragraphs.

The present invention will now be described in further detail by theexamples provided below.

EXAMPLES 1. Measuring Methods

The following definitions of terms and determination methods apply forthe above general description of the invention as well as to the belowexamples unless otherwise defined.

Calculation of comonomer content of the elastomeric copolymer fraction,i.e. the polymer fraction produced in the third reactor (R3), of thefirst heterophasic propylene copolymer (HECO1):

$\begin{matrix}{\frac{{C({PP})} - {{w\left( {{PP}\; 12} \right)} \times {C\left( {{PP}\; 12} \right)}}}{w\left( {{PP}\; 3} \right)} = {C\left( {{PP}\; 3} \right)}} & (I)\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fraction, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(PP3) is the weight fraction [in wt.-%] of the elastomeric    propylene copolymer fraction, i.e. the polymer produced in the third    reactor (R3),-   C(PP12) is the comonomer content [in mol-%] of the first and second    propylene polymer fraction, i.e. the polymer produced in the first    and second reactor (R1+R2),-   C(PP) is the comonomer content [in mol-%] of the first propylene    polymer fraction, the second propylene polymer fraction and the    elastomeric propylene copolymer fraction, i.e. polymer produced in    the first, second and third reactor (R1+R2+R3),-   C(PP3) is the calculated comonomer content [in mol-%] of the    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the third reactor (R3).

Calculation of the xylene cold soluble (XCS) content of the elastomericpropylene copolymer fraction, i.e. the polymer fraction produced in thethird reactor (R3), of the first heterophasic propylene copolymer(HECO1):

$\begin{matrix}{\frac{{{XS}({HECO})} - {{w\left( {{PP}\; 12} \right)} \times {{XS}\left( {{PP}\; 12} \right)}}}{w(E)} = {{XS}(E)}} & ({II})\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fraction, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(E) is the weight fraction [in wt.-%] of the elastomeric propylene    copolymer fraction, i.e. the polymer produced in the third reactor    (R3)-   XS(PP12) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second propylene polymer fraction, i.e. the polymer    produced in the first and second reactor (R1+R2),-   XS(HECO) is the xylene cold soluble (XCS) content [in wt.-%] of the    first propylene polymer fraction, the second propylene polymer    fraction and the elastomeric propylene copolymer fraction, i.e.    polymer produced in the first, second reactor and third reactor    (R1+R2+R3),-   XS(E) is the calculated xylene cold soluble (XCS) content [in wt.-%]    of the elastomeric propylene copolymer fraction, i.e. the polymer    produced in the second and third reactor (R2+3).

Calculation of melt flow rate MFR₂ (230° C.) of the elastomericpropylene copolymer fraction, i.e. the polymer fraction produced in thethird reactor (R3), of the first heterophasic propylene copolymer(HECO1):

$\begin{matrix}{{{MFR}\left( {{PP}\; 3} \right)} = 10^{\lbrack\frac{{\log {({{MFR}{({PP})}})}} - {{w{({{PP}\; 12})}} \times {\log {({{MFR}{({{PP}\; 12})}})}}}}{w{({{PP}\; 3})}}\rbrack}} & ({III})\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(PP3) is the weight fraction [in wt.-%] of the elastomeric    propylene copolymer fraction, i.e. the polymer produced in the third    reactor (R3),-   MFR(PP12) is the melt flow rate MFR₂ (230° C.) [in g/10 min] of the    first and second propylene fractions, i.e. the polymer produced in    the first and second reactor (R1+R2),-   MFR(PP) is the melt flow rate MFR₂ (230° C.) [in g/10 min] of the    first and second propylene polymer fractions and the elastomeric    propylene copolymer fraction, i.e. the polymer produced in the    first, second and third reactor (R1+R2+R3),-   MFR(PP3) is the calculated melt flow rate MFR₂ (230° C.) [in g/10    min] of the elastomeric propylene copolymer fraction, i.e. the    polymer produced in the third reactor (R3).

Calculation of comonomer content of the elastomeric propylene copolymerfraction, i.e. the polymer fraction produced in the third reactor (R3),of the first heterophasic propylene copolymer (HECO1):

$\begin{matrix}{\frac{{C({HECO})} - {{w({PP})} \times {C({PP})}}}{w(E)} = {C(E)}} & ({IV})\end{matrix}$

wherein

-   w(PP) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(E) is the weight fraction [in wt.-%] of the elastomeric propylene    copolymer, i.e. of the polymer produced in the third reactor (R3),-   C(PP) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   C(HECO) is the comonomer content [in mol-%] of the propylene    copolymer, i.e. is the comonomer content [in mol-%] of the polymer    obtained after polymerization in the third reactor (R3),-   C(E) is the calculated comonomer content [in mol-%] of the    elastomeric propylene copolymer fraction, i.e. of the polymer    produced in the third reactor (R3).

Calculation of comonomer content of the first elastomeric propylenecopolymer fraction, i.e. the polymer fraction produced in the thirdreactor (R3), of the second heterophasic propylene copolymer (HECO2):

$\begin{matrix}{\frac{{C({PP})} - {{w\left( {{PP}\; 12} \right)} \times {C\left( {{PP}\; 12} \right)}}}{w\left( {{PP}\; 3} \right)} = {C\left( {{PP}\; 3} \right)}} & (V)\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(PP3) is the weight fraction [in wt.-%] of the first elastomeric    propylene copolymer fraction, i.e. the polymer produced in the third    reactor (R3),-   C(PP12) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   C(PP) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions and the first elastomeric propylene    copolymer fraction, i.e. the polymer produced in the first, second    and third reactor (R1+R2+R3),-   C(PP2) is the calculated comonomer content [in mol-%] of the first    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the third reactor (R3).

Calculation of comonomer content of the second elastomeric propylenecopolymer fraction, i.e. the polymer fraction produced in the fourthreactor (R3), of the second heterophasic propylene copolymer (HECO2):

$\begin{matrix}{\frac{{C({PP})} - {{w\left( {{PP}\; 123} \right)} \times {C\left( {{PP}\; 123} \right)}}}{w\left( {{PP}\; 4} \right)} = {C\left( {{PP}\; 4} \right)}} & ({VI})\end{matrix}$

wherein

-   w(PP123) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions and the first elastomeric propylene    copolymer fraction, i.e. the polymer produced in the first, second    and third reactor (R1+R2+R3),-   w(PP4) is the weight fraction [in wt.-%] of second elastomeric    propylene copolymer fraction, i.e. the polymer produced in the    fourth reactor (R4),-   C(PP123) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions and the first elastomeric propylene    copolymer fraction, i.e. the polymer produced in the first, second    and third reactor (R1+R2+R3),-   C(PP) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions and the first and second elastomeric    propylene copolymer fractions, i.e. the polymer produced in the    first, second, third and fourth reactor (R1+R2+R3),-   C(PP4) is the calculated comonomer content [in mol-%] of the second    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the fourth reactor (R4).

Calculation of the xylene cold soluble (XCS) content of the elastomericpropylene copolymer fraction, i.e. the polymer fraction produced in thethird and fourth reactor (R3+R4), of the second heterophasic propylenecopolymer (HECO2):

$\begin{matrix}{\frac{{{XS}({HECO})} - {{w\left( {{PP}\; 12} \right)} \times {{XS}\left( {{PP}\; 12} \right)}}}{w(E)} = {{XS}(E)}} & ({VII})\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(E) is the weight fraction [in wt.-%] of the elastomeric propylene    copolymer fraction, i.e. the polymer produced in the third and    fourth reactor (R3+R4)-   XS(PP12) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second propylene polymer fractions, i.e. the polymer    produced in the first and second reactor (R1+R2),-   XS(HECO) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second propylene polymer fractions and the elastomeric    propylene copolymer fraction, i.e. polymer produced in the first,    second, third and fourth (R1+R2+R3+R4),-   XS(E) is the calculated xylene cold soluble (XCS) content [in wt.-%]    of the elastomeric propylene copolymer fraction, i.e. the polymer    produced in the third and fourth reactor (R3+R4).

Calculation of the xylene cold soluble (XCS) content of the firstelastomeric propylene copolymer fraction, i.e. the polymer fractionproduced in the third reactor (R3), of the second heterophasic propylenecopolymer (HECO2):

$\begin{matrix}{\frac{{{XS}({PP})} - {{w\left( {{PP}\; 12} \right)} \times {{XS}\left( {{PP}\; 12} \right)}}}{w\left( {{PP}\; 3} \right)} = {{XS}\left( {{PP}\; 3} \right)}} & ({VIII})\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(PP3) is the weight fraction [in wt.-%] of the first elastomeric    propylene copolymer fraction, i.e. the polymer produced in the third    reactor (R3)-   XS(PP12) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second elastomeric propylene polymer fractions, i.e. the    polymer produced in the first and second reactor (R1+R2),-   XS(PP) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second propylene polymer fraction and the first    elastomeric propylene copolymer fraction, i.e. polymer produced in    the first, second and third reactor (R1+R2+R3),-   XS(PP3) is the calculated xylene cold soluble (XCS) content [in    wt.-%] of the first elastomeric propylene copolymer fraction, i.e.    the polymer produced in the third reactor (R3).

Calculation of the xylene cold soluble (XCS) content of the secondelastomeric propylene copolymer fraction, i.e. the polymer fractionproduced in the fourth reactor (R4):

$\begin{matrix}{\frac{{{XS}({PP})} - {{w\left( {{PP}\; 123} \right)} \times {{XS}\left( {{PP}\; 123} \right)}}}{w\left( {{PP}\; 4} \right)} = {{XS}\left( {{PP}\; 4} \right)}} & ({IX})\end{matrix}$

wherein

-   w(PP123) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions and the first elastomeric propylene    copolymer fraction, i.e. the polymer produced in the first, second    and third reactor (R1+R2+R3),-   w(PP4) is the weight fraction [in wt.-%] of the second propylene    copolymer fraction, i.e. the polymer produced in the fourth reactor    (R4)-   XS(PP123) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second propylene polymer fractions and the first    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the first, second and third reactor (R1+R2+R3),-   XS(PP) is the xylene cold soluble (XCS) content [in wt.-%] of the    first and second propylene polymer fractions and the first and    second elastomeric propylene copolymer fractions, i.e. polymer    produced in the first, second reactor and third reactor    (R1+R2+R3+R4),-   XS(PP4) is the calculated xylene cold soluble (XCS) content [in    wt.-%] of the second elastomeric propylene copolymer fraction, i.e.    the polymer produced in the fourth reactor (R4).

Calculation of melt flow rate MFR₂ (230° C.) of the second propylenepolymer fraction, i.e. the polymer fraction produced in the secondreactor (R2), of the second heterophasic propylene copolymer (HECO2):

$\begin{matrix}{{{MFR}\left( {{PP}\; 2} \right)} = 10^{\lbrack\frac{{\log {({{MFR}{({PP})}})}} - {{w{({{PP}\; 1})}} \times {\log {({{MFR}{({{PP}\; 1})}})}}}}{w{({{PP}\; 2})}}\rbrack}} & (X)\end{matrix}$

wherein

-   w(PP1) is the weight fraction [in wt.-%] of the first propylene    polymer fraction, i.e. the polymer produced in the first reactor    (R1),-   w(PP2) is the weight fraction [in wt.-%] of the first second    propylene polymer fraction, i.e. the polymer produced in the second    reactor (R2),-   MFR(PP1) is the melt flow rate MFR₂ (230° C.) [in g/10 min] of the    first propylene polymer fraction, i.e. the polymer produced in the    first reactor (R1),-   MFR(PP) is the melt flow rate MFR₂ (230° C.) [in g/10 min] of the    first and second propylene polymer fractions, i.e. the polymer    produced in the first and second reactor (R1+R2),-   MFR(PP2) is the calculated melt flow rate MFR₂ (230° C.) [in g/10    min] of the first propylene polymer fraction, i.e. the polymer    produced in the second reactor (R2).

Calculation of the intrinsic viscosity of the xylene soluble fraction ofthe first elastomeric propylene copolymer fraction, i.e. the polymerfraction produced in the third reactor (R3), of the second heterophasicpropylene copolymer (HECO2):

$\begin{matrix}{\frac{{{IV}({PP})} - {{{XCS}\left( {{PP}\; 12} \right)} \times {{IV}\left( {{PP}\; 12} \right)}}}{{XCS}\left( {{PP}\; 3} \right)} = {{IV}\left( {{PP}\; 3} \right)}} & ({XI})\end{matrix}$

wherein

-   XCS(PP12) is the xylene soluble fraction [in wt.-%] of the first and    second propylene polymer fractions, i.e. the polymer produced in the    first and second reactor (R1+R2),-   XCS(PP3) is the xylene soluble fraction [in wt.-%] of the first    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the third reactor (R3),-   IV(PP12) is the intrinsic viscosity [in dl/g] of the xylene soluble    fraction of the first and second propylene polymer fractions, i.e.    the polymer produced in the first and second reactor (R1+R2),-   IV(PP) is the intrinsic viscosity [in dl/g] of the xylene soluble    fraction of the first and second propylene polymer fractions and the    first elastomeric propylene copolymer fraction, i.e. polymer    produced in the first, second and third reactor (R1+R2+R3),-   IV(PP3) is the calculated intrinsic viscosity [in dl/g] of the    xylene soluble fraction of the first elastomeric propylene copolymer    fraction, i.e. the polymer produced in the third reactor (R3).

Calculation of the intrinsic viscosity of the xylene soluble fraction ofthe second elastomeric propylene copolymer fraction, i.e. the polymerfraction produced in the fourth reactor (R4), of the second heterophasicpropylene copolymer (HECO2):

$\begin{matrix}{\frac{{{IV}({PP})} - {{{XCS}\left( {{PP}\; 123} \right)} \times {{IV}\left( {{PP}\; 123} \right)}}}{{XCS}\left( {{PP}\; 4} \right)} = {{IV}\left( {{PP}\; 4} \right)}} & ({XII})\end{matrix}$

wherein

-   XCS(PP123) is the xylene soluble fraction [in wt.-%] of the first    and second propylene polymer fractions and the first elastomeric    propylene copolymer fraction, i.e. the polymer produced in the    first, second and third reactor (R1+R2+R3),-   XCS(PP4) is the xylene soluble fraction [in wt.-%] of second    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the fourth reactor (R4),-   IV(PP123) is the intrinsic viscosity [in dl/g] of the xylene soluble    fraction of the first and second propylene polymer fractions and the    first elastomeric propylene copolymer fraction, i.e. the polymer    produced in the first, second and third reactor (R1+R2+R3),-   IV(PP) is the intrinsic viscosity [in dl/g] of the xylene soluble    fraction of the first and second propylene polymer fractions and the    first and second elastomeric propylene copolymer fractions, i.e.    polymer produced in the first, second, third and fourth reactor    (R1+R2+R3+R4),-   IV(PP4) is the calculated intrinsic viscosity [in dl/g] of the    xylene soluble fraction of the second elastomeric propylene    copolymer fraction, i.e. the polymer produced in the fourth reactor    (R4).

Calculation of comonomer content of the elastomeric propylene copolymerfraction, i.e. the polymer fraction produced in the third and fourthreactor (R3+R4), of the second heterophasic propylene copolymer (HECO2):

$\begin{matrix}{\frac{{C({HECO})} - {{w\left( {{PP}\; 12} \right)} \times {C\left( {{PP}\; 12} \right)}}}{w(E)} = {C(E)}} & ({XIII})\end{matrix}$

wherein

-   w(PP12) is the weight fraction [in wt.-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   w(E) is the weight fraction [in wt.-%] of the elastomeric propylene    copolymer fraction, i.e. the polymer produced in the third and    fourth reactor (R3+R4)-   C(PP12) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions, i.e. the polymer produced in the first    and second reactor (R1+R2),-   C(HECO) is the comonomer content [in mol-%] of the first and second    propylene polymer fractions and the elastomeric propylene copolymer,    i.e. polymer produced in the first, second, third and fourth    (R1+R2+R3+R4),-   C(E) is the calculated comonomer content [in mol-%] of the    elastomeric propylene copolymer fraction, i.e. the polymer produced    in the third and fourth reactor (R3+R4).-   MFR₂ (230° C.) is measured according to ISO 1133 (230° C., 2.16 kg    load).-   MFR₂ (190° C.) is measured according to ISO 1133 (190° C., 2.16 kg    load).

Quantification of Microstructure by NMR Spectroscopy

Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used toquantify the comonomer content and comonomer sequence distribution ofthe polymers. Quantitative ¹³C {¹H} NMR spectra were recorded in thesolution-state using a Bruker Advance III 400 NMR spectrometer operatingat 400.15 and 100.62 MHz for ¹H and ¹³C respectively. All spectra wererecorded using a ¹³C optimised 10 mm extended temperature probehead at125° C. using nitrogen gas for all pneumatics. Approximately 200 mg ofmaterial was dissolved in 3 ml of 1,2-tetrachloroethane-d₂ (TCE-d₂)along with chromium-(III)-acetylacetonate (Cr(acac)₃) resulting in a 65mM solution of relaxation agent in solvent (Singh, G., Kothari, A.,Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure a homogenoussolution, after initial sample preparation in a heat block, the NMR tubewas further heated in a rotatary oven for at least 1 hour. Uponinsertion into the magnet the tube was spun at 10 Hz. This setup waschosen primarily for the high resolution and quantitatively needed foraccurate ethylene content quantification. Standard single-pulseexcitation was employed without NOE, using an optimised tip angle, 1 srecycle delay and a bi-level WALTZ16 decoupling scheme (Zhou, Z.,Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D.Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere,P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol.Rapid Commun. 2007, 28, 1128). A total of 6144 (6 k) transients wereacquired per spectra. Quantitative ¹³C {¹H} NMR spectra were processed,integrated and relevant quantitative properties determined from theintegrals using proprietary computer programs. All chemical shifts wereindirectly referenced to the central methylene group of the ethyleneblock (EEE) at 30.00 ppm using the chemical shift of the solvent. Thisapproach allowed comparable referencing even when this structural unitwas not present. Characteristic signals corresponding to theincorporation of ethylene were observed Cheng, H. N., Macromolecules 17(1984), 1950).

For polypropylene homopolymers all chemical shifts are internallyreferenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

Characteristic signals corresponding to regio defects (Resconi, L.,Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang,W-J., Zhu, S., Macromolecules 33 (2000), 1157; Cheng, H. N.,Macromolecules 17 (1984), 1950) or comonomer were observed.

The tacticity distribution was quantified through integration of themethyl region between 23.6-19.7 ppm correcting for any sites not relatedto the stereo sequences of interest (Busico, V., Cipullo, R., Prog.Polym. Sci. 26 (2001) 443; Busico, V., Cipullo, R., Monaco, G.,Vacatello, M., Segre, A. L., Macromolecules 30 (1997) 6251).

Specifically the influence of regio defects and comonomer on thequantification of the tacticity distribution was corrected for bysubtraction of representative regio defect and comonomer integrals fromthe specific integral regions of the stereo sequences.

The isotacticity was determined at the pentad level and reported as thepercentage of isotactic pentad (mmmm) sequences with respect to allpentad sequences:

[mmmm]%=100*(mmmm/sum of all pentads)

The presence of 2,1 erythro regio defects was indicated by the presenceof the two methyl sites at 17.7 and 17.2 ppm and confirmed by othercharacteristic sites.

Characteristic signals corresponding to other types of regio defectswere not observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F.,Chem. Rev. 2000, 100, 1253).

The amount of 2,1 erythro regio defects was quantified using the averageintegral of the two characteristic methyl sites at 17.7 and 17.2 ppm:

P _(21e) =I _(e6) +I _(e8))/2

The amount of 1,2 primary inserted propene was quantified based on themethyl region with correction undertaken for sites included in thisregion not related to primary insertion and for primary insertion sitesexcluded from this region:

P ₁₂ =I _(CH3) +P _(12e)

The total amount of propene was quantified as the sum of primaryinserted propene and all other present regio defects:

P _(total) =P ₁₂ +P _(21e)

The mole percent of 2,1 erythro regio defects was quantified withrespect to all propene:

[21e] mol %=100*(P _(21e) /P _(total))

For copolymers characteristic signals corresponding to the incorporationof ethylene were observed (Cheng, H. N., Macromolecules 17 (1984),1950).

With regio defects also observed (Resconi, L., Cavallo, L., Fait, A.,Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, W-J., Zhu, S.,Macromolecules 33 (2000), 1157; Cheng, H. N., Macromolecules 17 (1984),1950) correction for the influence of such defects on the comonomercontent was required.

The comonomer fraction was quantified using the method of Wang et. al.(Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157) throughintegration of multiple signals across the whole spectral region in the¹³C {¹H} spectra. This method was chosen for its robust nature andability to account for the presence of regio-defects when needed.Integral regions were slightly adjusted to increase applicability acrossthe whole range of encountered comonomer contents.

For systems where only isolated ethylene in PPEPP sequences was observedthe method of Wang et. al. was modified to reduce the influence ofnon-zero integrals of sites that are known to not be present. Thisapproach reduced the overestimation of ethylene content for such systemsand was achieved by reduction of the number of sites used to determinethe absolute ethylene content to:

E=0.5(Sββ+Sβγ+Sβδ+0.5(Sαβ+Sαγ))

Through the use of this set of sites the corresponding integral equationbecomes:

E=0.5(I _(H) +I _(G)+0.5(I _(C) +I _(D)))

using the same notation used in the article of Wang et. al. (Wang, W-J.,Zhu, S., Macromolecules 33 (2000), 1157). Equations used for absolutepropylene content were not modified.

The mole percent comonomer incorporation was calculated from the molefraction:

E[mol %]=100*fE

The weight percent comonomer incorporation was calculated from the molefraction:

E[wt %]=100*(fE*28.06)/((fE*28.06)+((1−fE)*42.08))

The comonomer sequence distribution at the triad level was determinedusing the analysis method of Kakugo et al. (Kakugo, M., Naito, Y.,Mizunuma, K., Miyatake, T. Macromolecules 15 (1982) 1150). This methodwas chosen for its robust nature and integration regions slightlyadjusted to increase applicability to a wider range of comonomercontents.

Number Average Molecular Weight (M_(n)), Weight Average Molecular Weight(M_(w)) and Molecular Weight Distribution (MWD) Molecular weightaverages (Mw, Mn), and the molecular weight distribution (MWD), i.e. theMw/Mn (wherein Mn is the number average molecular weight and Mw is theweight average molecular weight), were determined by Gel PermeationChromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99. APolymerChar GPC instrument, equipped with infrared (IR) detector wasused with 3× Olexis and 1× Olexis Guard columns from PolymerLaboratories and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg/L2,6-Di tert butyl-4-methyl-phenol) as solvent at 160° C. and at aconstant flow rate of 1 mL/min 200 μL. of sample solution were injectedper analysis. The column set was calibrated using universal calibration(according to ISO 16014-2:2003) with at least 15 narrow MWD polystyrene(PS) standards in the range of 0.5 kg/mol to 11 500 kg/mol. Mark Houwinkconstants for PS, PE and PP used are as described per ASTM D 6474-99.All samples were prepared by dissolving 5.0-9.0 mg of polymer in 8 mL(at 160° C.) of stabilized TCB (same as mobile phase) for 2.5 hours forPP or 3 hours for PE at max. 160° C. under continuous gentle shaking inthe autosampler of the GPC instrument. DSC analysis, melting temperature(Tm). crystallization temperature (Tc): measured with a TA InstrumentQ2000 differential scanning calorimeter (DSC) on 5 to 7 mg samples. DSCrun according to ISO 11357/part 3/method C2 in a heat/cool/heat cyclewith a scan rate of 10° C./min in the temperature range of −30 to +230°C. Crystallization temperature was determined from the cooling step,while melting temperature was determined from the heating scan.

Intrinsic viscosity is measured according to DIN ISO 1628/1, October1999 (in Decalin at 135° C.).

Density is measured according to ISO 1183-187. Sample preparation isdone by compression moulding in accordance with ISO 1872-2:2007.

The xylene solubles (XCS, wt.-%): Content of xylene cold solubles (XCS)is determined at 25° C. according ISO 16152; first edition; 2005-07-01.The part which remains insoluble is the xylene cold insoluble (XCI)fraction.

Flexural Modulus: The flexural modulus was determined in 3-point-bendingaccording to ISO 178 on 80×10×4 mm³ test bars injection molded at 23° C.in line with EN ISO 1873-2.

Charpy notched impact test: The charpy notched impact strength (CharpyNIS) was measured according to ISO 179 2C/DIN 53453 at 23° C. and −20°C., using injection molded bar test specimens of 80×10×4 mm prepared inaccordance with ISO 294-1:1996

Shrinkage in flow and shrinkage cross flow were determined on film gateinjection moulded plaques: One is a sector (radius 300 mm and openingangle of 20°) and the other one a stripe (340×65 mm). The two specimensare injection moulded at the same time in different thicknesses and backpressures (2 mm and 300, 400, 500 bars; 2.8 mm and 300, 400, 500 bars;3.5 mm and 300, 400, 500 bars). The melt temperature is 240° C. and thetemperature of the tool 25° C. Average flow front velocity is 3.0±0.2mm/s for the 2 mm tool, 3.5±0.2 mm/s for the 2.8 mm tool and. 0±0.2 mm/sfor the 3.5 mm tool.

After the injection moulding process the shrinkage of the specimens ismeasured at 23° C. and 50% humidity. The measurement intervals are 1, 4,24, 48 and 96 hours after the injection moulding. To determine theshrinkage 83 and 71 measurement points (generated by eroded dots on thetool surface) of the sector and the stripe, respectively, are recordedwith a robot. Both, in flow and cross flow shrinkage of the 2.8 mm thickplates exposed to a back pressure of 400 bars at 96 hours after theinjection moulding process are reported as final results.

Surface Appearance of Compact and Foamed Parts

The tendency to show flow marks was examined with a method as describedbelow. This method is described in detail in WO 2010/149529, which isincorporated herein in its entirety.

An optical measurement system, as described by Sybille Frank et al. inPPS 25 Intern. Conf. Polym. Proc. Soc 2009 or Proceedings of the SPIE,Volume 6831, pp 68130T-68130T-8 (2008) was used for characterizing thesurface quality.

This method consists of two aspects:

1. Image Recording:

The basic principle of the measurement system is to illuminate theplates with a defined light source (LED) in a closed environment and torecord an image with a CCD-camera system.

A schematic setup is given in FIG. 1.

2. Image Analysis:

The specimen is floodlit from one side and the upwards reflected portionof the light is deflected via two mirrors to a CCD-sensor. The suchcreated grey value image is analyzed in lines. From the recordeddeviations of grey values the mean square error average (MSEaverage) ormean square error maximum (MSEmax) values are calculated allowing aquantification of surface quality/homogeneity, i.e. the higher the MSEvalue the more pronounced is the surface defect. MSEaverage and MSEmaxvalues are not comparable. Generally, for one and the same material, thetendency to flow marks increases when the injection speed is increased.

The MSEaverage values were collected on compact injection-mouldedplaques 440×148×2.8 mm produced with grain G1. The plaques wereinjection-moulded with different filling times of 1.5, 3 and 6 secrespectively.

Further Conditions:

Melt temperature: 240° C.

Mould temperature 30° C.

Dynamic pressure: 10 bar hydraulic

The MSEmax values were collected on compact and foamed injection-mouldedplaques 210×148×2 mm produced with a one-point gating system and a grainmarked here as G2, which differs from G1. The plaques wereinjection-moulded with filling time of 0.8 s. Hydrocerol ITP 825 fromClariant, with a decomposition temperature of 200° C. was used as achemical blowing agent. The blowing agent was added during theconversion step in a form of a masterbatch, which contains 40% of activesubstance defined as a citric acid [www.clariant.com].

Cell structure of the foamed parts was determined by light microscopyfrom a cross-section of the foamed injection-molded plate.

Maximum force at break was determined on plaques with dimensions148×148×2 mm during instrumented falling weight impact testing accordingto ISO 6603-2. The test was performed at room temperature with alubricated tup with a diameter of 20 mm and impact velocity of 10 mm/s.The maximum force at break was determined as the maximum peak at theforce-deformation curve collected during the test.

Compression test was performed on 10×10×2 mm plaques at room temperatureaccording to ISO 604: 2002. The tests were carried out on a Zwick Z010Umachine with a test speed of 0.87 mm/min at room temperature. Thecompressive stress was determined at 1 mm deformation. Thus, thecompressive stress is defined as the force at break at 1 mm deformationdivided by the specimen area at the beginning of the experiment.

2. Examples

Preparation of the Catalyst for HECO1, HECO2 and HECO2a

First, 0.1 mol of MgCl2×3 EtOH was suspended under inert conditions in250 ml of decane in a reactor at atmospheric pressure. The solution wascooled to the temperature of −15° C. 5 and 300 ml of cold TiCl4 wasadded while maintaining the temperature at said level. Then, thetemperature of the slurry was increased slowly to 20° C. At thistemperature, 0.02 mol of dioctylphthalate (DOP) was added to the slurry.After the addition of the phthalate, the temperature was raised to 135°C. during 90 minutes and the slurry was allowed to stand for 60 minutes.Then, another 300 ml of TiCl4 was added and the temperature was kept at135° C. 10 for 120 minutes. After this, the catalyst was filtered fromthe liquid and washed six times with 300 ml heptane at 80° C. Then, thesolid catalyst component was filtered and dried. Catalyst and itspreparation concept is described in general e.g. in patent publicationsEP 491566, EP 591224 and EP 586390.

The catalyst was further modified (VCH modification of the catalyst). 35ml of mineral oil (Paraffinum Liquidum PL68) was added to a 125 mlstainless steel reactor followed by 0.82 g of triethyl aluminium (TEAL)and 0.33 g of dicyclopentyl dimethoxy silane (donor D) under inertconditions at room temperature. After 10 minutes 5.0 g of the catalystprepared above (Ti content 1.4 wt.-%) was added and after additionally20 minutes 5.0 g of vinylcyclohexane (VCH) was added. The temperaturewas increased to 60° C. during 30 minutes and was kept there for 20hours. Finally, the temperature was decreased to 20° C. and theconcentration of unreacted VCH in the oil/catalyst mixture was analysedand was found to be 200 ppm weight.

Preparation of the catalyst for HECO2b 80 mg of ZN104-catalyst ofLyondellBasell is activated for 5 minutes with a mixture ofTriethylaluminium (TEAL; solution in hexane 1 mol/1) andDicyclopentyldimethoxysilane as donor (0.3 mol/l in hexane)—in a molarratio of 18.7 (Co/ED) after a contact time of 5 min and 10 ml hexane ina catalyst feeder. The molar ratio of TEAL and Ti of catalyst is 220(Co/TC)). After activation the catalyst is spilled with 250 g propyleneinto the stirred reactor with a temperature of 23° C. Stirring speed ishold at 250 rpm. After 6 min prepolymersation at 23° C. thepolymerisation starts as indicated in table 1.

TABLE 1 Preparation of HECO1, HECO2, HECO2a and HECO2b HECO1 HECO2HECO2a HECO2b Prepolymer- ization TEAL/Ti [mol/mol] 200 200 220 220TEAL/donor [mol/mol] 5.01 10 7.3 18 Temperature [° C.] 30 30 30 30res.time [h] 0.17 0.26 0.08 0.1 Loop Temperature [° C.] 80 76 72 70Split [%] 34 35 35 32.5 H2/C3 ratio [mol/kmol] 7 25 15 14 C2/C3 ratio[mol/kmol] 0 0 0 0 MFR₂ [g/10 min] 162 160 55 35 XCS [wt.-%] 2.0 2.1 2.02.0 C2 content [mol-%] 0 0 0 0.0 GPR 1 Temperature [° C.] 95 80 80 78Pressure [kPa] 1500 2400 2231 2214 Split [%] 45 40 30 34.5 H2/C3 ratio[mol/kmol] 84 45 150 78 C2/C3 ratio [mol/kmol] 0 0 0 0 MFR₂ [g/10 min]159 55 55 35 XCS [wt.-%] 2.9 2.0 2.0 2.0 C2 content [mol-%] 0 0 0 0 GPR2 Temperature [° C.] 85 67 70 71 Pressure [kPa] 1400 2100 2291 2292Split [%] 21 15 19 21 C2/C3 ratio [mol/kmol] 600 242 584 715 H2/C2 ratio[mol/kmol] 170 23 117 219 MFR₂ [g/10 min] 66 20 11 12 XCS [wt.-%] 20 1818 19 IV (XCS) [dl/g] 2.9 nd nd nd C2 (XCS) [mol-%] 53 nd nd nd C2content [mol-%] 18 10 18 12 GPR 3 Temperature [° C.] 67 85 83 Pressurebar 1500 1421 1383 Split [%] 10 16 12 C2/C3 ratio [mol/kmol] 250 585 747H2/C2 ratio [mol/kmol] 22 93 203 MFR₂ [g/10 min] 5 11 13 XCS [wt.-%] 2532 30 IV (XCS) [dl/g] 6.3 3.1 2.2 C2 (XCS) [mol-%] 25.7 48 55 C2 content[mol-%] 11.2 19 22 C2 ethylene H2/C3 ratio hydrogen/propylene ratioC2/C3 ratio ethylene/propylene ratio H2/C2 ratio hydrogen/ethylene ratioGPR 1/2/3 1st/2nd/3rd gas phase reactor Loop Loop reactor

A Borstar PP pilot plant comprised of a stirred-tank prepolymerizationreactor, a liquid-bulk loop reactor, and three gas phase reactors (GPR1to GPR3) was used for the main polymerization. The resulting polymerpowders were compounded in a co-rotating twin-screw extruder CoperionZSK 57 at 220° C. with 0.2 wt.-% of Irganox B225 (1:1-blend of Irganox1010(Pentaerythrityl-tetrakis(3-(3′,5′-di-tert.butyl-4-hydroxytoluyl)-propionateand tris (2,4-di-t-5 butylphenyl) phosphate) phosphite) of BASF AG,Germany) and 0.05 wt.-% calcium stearate.

Preparation of the Composition (C)

HECO1 and HECO2 (inventive), HECO2a (comparative) or HECO2b(comparative) and optionally PL and HDPE were melt blended on aco-rotating twin screw extruder with 0.1 wt.-% of Songnox 1010FF(Pentaerythrityl-tetrakis(3-(3′,5′-di-tert. butyl-4-hydroxyphenyl)),0.07 wt.-% Kinox-68 G (Tris (2,4-di-t-butylphenyl) phosphite) from HPLAdditives, 0.16 wt % hindered amine light stabilizers which were mixedin a 1:1 blend based on Sabostab UV119 (1,3,5-Triazine-2,4,6-triamine)and Hilite 77(G)(Bis-(2,2,6,6-tetramethyl-4-piperidyl)-sebacate), 0.1 wt% NA11UH (Sodium 2,2′-methylene bis-(4,6-di-tert. butylphenyl)phosphate) and 0.1 wt % Erucamide (13-docosenamide). The polymer meltmixture was discharged and pelletized.

TABLE 2 Properties of comparative and inventive examples collected on 2mm compact and chemically injection-moulded foamed plates. CE1 CE2 CE3IE1 IE2 IE3 IE4 HECO1 [wt.-%] 42.5 56.5 56.5 42.5 42.5 56.5 56.5 HECO2[wt.-%] 26.5 26.5 25.5 25.5 HECO2a [wt.-%] 26.5 25.5 HECO2b [wt.-%] 25.5PL [wt.-%] 8.0 8.0 8.0 HDPE [wt.-%] 5.0 5.0 5.0 Wollastonite [wt.-%]14.5 14.5 14.5 14.5 14.5 Talc1 [wt.-%] 14.5 Talc2 [wt.-%] 14.5 Pigments[wt.-%] 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Additives [wt.-%] 2 2 2 2 2 2 2Properties of compact parts MFR [g/10 min] 28.0 39.0 36.0 21.0 20.0 32.027.0 SH in flow sector, 96 h [—] 0.55 0.51 0.54 0.52 0.81 0.64 0.77 SHcross flow sector, 96 h [—] 1.40 1.30 1.4 1.35 1.09 1.56 1.04 SHisotropic sector, 96 h [—] 1.02 1.00 1.00 1.00 1.00 1.15 0.94 FlexuralModulus [MPa] 2157 2613 2663 2272 1886 2678 2505 Charpy impact strength,+23° C. [kJ/m²] 10 5 5 16 14 6 6 Charpy impact strength, −20° C. [kJ/m²]nd 3.6 nd 2.5 nd nd nd Maximum force at break N 1250 1300 1400 1600 17501850 Compressive stress at 1 mm MPa 70 75 70 69 80 90 MSEaverage, 1.5 s,G1 [—] 18 7 6 4 3 4 3 MSEmax, 0.8 s, G2 [—] 45 40 40 42 41 45 Propertiesof foamed parts Cell size [μm] 90 80 70 70 60 60 60 Cell structure [—]coarse coarse coarse fine fine fine fine Part surface [—] poor poor poorgood good good good Maximum force at break N nd 900 1000 1200 1300 14001650 Compressive stress at 1 mm MPa nd 65 65 69 69 75 75 MSEmax, G2 nd43 43 41 43 40 43 HECO2a is the commercial heterophasic propylenecopolymer EE050AE of Borealis HECO2b is the commercial heterophasicpropylene copolymer EE041AE of Borealis PL is the commercialethylene-octene copolymer Queo8230 of Borealis having a density of 0.880g/cm³, a melt flow rate MFR₂ (190° C.) of 30.0 g/10 min and an 1-octenecontent of 7.0 mol-%. HDPE is the commercial high density polyethyleneMG9601 of Borealis Wollastonite is the commercial Wollastonite Nyglos 8of Imerys Talc1 is the commercial Talc Jetfine 3CA of Luzenac Talc2 isthe commercial Talc HAR T84 of Luzenac Pigments is a masterbatch of 70wt.-% of linear density polyethylene (LDPE) and 30 wt.-% carbon black,with MFR (190° C./21.6 kg) of 15 g/10 min. Additives is a masterbatch ofSongnox 1010FF (Pentaerythrityl-tetrakis(3-(3′,5′-di-tert.butyl-4-hydroxyphenyl)), Kinox-68 G (Tris (2,4-di-t-butylphenyl)phosphite) from HPL Additives, hindered amine light stabilizers whichwere mixed in a 1:1 blend based on Sabostab UV119(1,3,5-Triazine-2,4,6-triamine) and Hilite77(G)(Bis-(2,2,6,6-tetramethyl-4-piperidyl)-sebacate), NA11UH (Sodium2,2′-methylene bis-(4,6-di-tert. butylphenyl) phosphate) and Erucamide(13-docosenamide) as outlined above.

1. A polypropylene composition (C), comprising: a) a first heterophasicpropylene copolymer (HECO1) having a comonomer content of the xylenesoluble fraction (XCS) equal or above 40.0 mol %, said firstheterophasic propylene copolymer comprising: i) a first matrix being afirst propylene polymer (M1) and ii) a first elastomeric propylenecopolymer (E1) being dispersed in said first matrix, b) a secondheterophasic propylene copolymer (HECO2) having a comonomer content ofthe xylene soluble fraction (XCS) below 39.0 mol %, said secondheterophasic propylene copolymer comprising: iii) a second matrix beinga second propylene polymer (M2) and iv) a second elastomeric propylenecopolymer (E1) being dispersed in said second matrix, c) an inorganicfiller (F), d) optionally a high density polyethylene (HDPE), and e)optionally a plastomer (PL) being a copolymer of ethylene and a C₄ to C₈α-olefin.
 2. The polypropylene composition (C) according to claim 1,wherein the xylene soluble fraction (XCS) of the second heterophasiccopolymer (HECO2) has an intrinsic viscosity (IV) above 3.5 dl/g.
 3. Thepolypropylene composition (C) according to claim 1, comprising: a) 40.0to 60.0 wt. % of the first heterophasic propylene copolymer (HECO1), b)21.0 to 31.0 wt. % of the second heterophasic propylene copolymer(HECO2), c) 10.0 to 20.0 wt. % of the inorganic filler (F), d)optionally 2.0 to 10.0 wt. % of the high density polyethylene (HDPE),and e) optionally 5.0 to 15.0 wt. % of the plastomer (PL) being acopolymer of ethylene and a C₄ to C₈ α-olefin, based on the overallpolypropylene composition (C).
 4. Polypropylene composition (C)according to claim 1, wherein: i) the matrix of the first heterophasicpropylene copolymer (HECO1) being the first propylene polymer (M1) has amelt flow rate MFR₂ (230° C.) determined according to ISO 1133 in therange of 120 to 500 g/10 min and ii) the matrix of the secondheterophasic propylene copolymer (HECO2) being the second propylenepolymer (M2) has a melt flow rate MFR₂ (230° C.) determined according toISO 1133 in the range of 40 to 170 g/10 min.
 5. The polypropylenecomposition (C) according to claim 1, wherein the first heterophasicpropylene copolymer (HECO1) has: i) a melt flow rate MFR₂ (230° C.)determined according to ISO 1133 in the range of 50 to 90 g/10 min,and/or ii) a comonomer content in the range of 20.0 to 50.0 mol %,and/or iii) a xylene soluble fraction (XCS) in the range of 10.0 to 35.0wt. %.
 6. The polypropylene composition (C) according to claim 1,wherein the second heterophasic propylene copolymer (HECO2) has: i) amelt flow rate MFR₂ (230° C.) determined according to ISO 1133 in therange of 1.0 to 15 g/10 min, and/or ii) a comonomer content in the rangeof 5.0 to 30.0 mol %, and/or iii) a xylene soluble fraction (XCS) in therange of 20.0 to 40.0 wt. %.
 7. Polypropylene composition (C) accordingto any one of the preceding claims, wherein the first propylene polymer(M1) and/or the second propylene polymer (M2) are propylenehomopolymers.
 8. The polypropylene composition (C) according to claim 1,wherein the first elastomeric propylene copolymer (E1) and/or the secondelastomeric propylene copolymer (E2) are copolymers of propylene andethylene.
 9. The polypropylene composition (C) according to claim 1,having a melt flow rate MFR₂ (230° C.) determined according to ISO 1133in the range of 10 to 40 g/10 min.
 10. The polypropylene composition (C)according to claim 1, wherein the plastomer (PL) is a copolymer ofethylene and 1-octene.
 11. The polypropylene composition (C) accordingto claim 1, wherein the inorganic filler (F) is talc and/orwollastonite.
 12. The polypropylene composition (C) according to claim1, wherein said polypropylene composition (C) is a foamablepolypropylene composition.
 13. (canceled)
 14. A foamed article,comprising the polypropylene composition (C) according to claim
 1. 15.The foamed article according to claim 13, wherein said foamed article isan automotive article.